1947-55 Tech Talk

With the introduction of the first six cylinder engine in 1929 the horn bracket location was between the two-hole base carburetor and intake manifold. The location was changed with the re-designed 216 cubic inch six cylinder in 1937. The attaching point actually was cast in to the intake manifold during production. There was no longer a steel attaching bracket that...

Then late 1947 through 1949 Chevy/GMC trucks had a very different wiring harness than later 1950 through 1955 years (actually, will not interchange with any other years). Its difference is seen just by raising the hood. On the firewall lower side of the voltage regulator is a vertical row of five fuses protected by a removable metal cover. Actually, when...

What an unusual body style! It was mostly bought by commercial companies to fill a void for those living in residential neighborhoods. General Motors realized an opportunity to design this unique body style truck. They were popular in medium to large cities, and later became so unpopular to potential second car and pickup owners. These were the years of the...

Most of us plan on replacing our valve cover gasket whenever it must be removed for maintenance on the rocker arm assembly. After being hot and cold so many times it has permanently attached itself to the engine head and valve cover. It is planned to always have a new gasket nearby each time the cover is removed. Good News...

Beginning in 1941 many of the GM long wheelbase (usually 1 ½ and 2 tons) trucks did not use cables to reach the rear brakes and hold the vehicle in its parked position. Debris from the tires could shorten the life of the under bed cables. Another method was created. A drum at the rear of the 4 speed transmission...

On our Feature Truck of the Month for February 2023 we described a method of attaching the larger original ¾ and 1 Ton hubcaps to a modern non-split 8 bolt wheel. Unheard of by Jim Carter Truck Parts until Glen Black of Lacey’s Springs, Alabama. He would not take no for an answer. He found a way to attach the...

With the introduction of any new vehicle, sometimes corrections must be quickly made that were missed during their design. We discover that even the more knowledgeable followers of the Advanced Design pickups and big trucks are not aware there were two different designs of “door handle remotes”. Generally Unknown Fact: The 1947-48 the doors, were opened by pushing the inside...

Be careful in purchasing used Advance Design rear bumper braces! Even the seller may not know there are two different shapes. When installed incorrectly, the rear bumper will not be in the correct position. The more common rear braces are on the half ton pickup. They are designed to lower the long horizontal bumper so the tailgate can swing down...

This is what we at Jim Carter Truck Parts (with 41 years’ experience) have learned about these very popular grilles.  Here is some grille bar data that many followers of the famous Advance Design trucks should find of interest.  This can be very important for a person on a hunt for a restorable grille. During your restoration of a ½...

Ever notice that older large GM trucks have split rim wheels painted one color? Thus, they give a more “plain” appearance. This is not the way these trucks where when new! From the factory, the narrow split rings were zinc plated. This was an important extra. It prevented them from rusting against the main wheel between tire changes. In northern...

A rare accessory indeed! In the days when some did not even lock their home doors, few would even consider buying a spare tire lock for their under bed pickup from their Chevrolet dealer. However, the 1937-50 Chevrolet / GMC Spare Tire Locking Device was available. A brass nut replaced the long factory hexagon nut used on the original spare...

Starting in 1934 an add-on fan shroud was offered for larger trucks used as delivery and freight haulers. The 1937-38 trucks had a new part number for the shroud. It was available for delivery vehicles involved in stop and go driving, heavy hauling, and school bus applications. The shroud was cataloged for ¾ ton, 1 ton, 1 ½ ton, and...

Somewhere between the factory all painted black bed wood and the planks that are sanded and clear-coated to show the attractive grain is a “middle ground”. Look at this very attractive creation! We were so impressed with this finished bed. It gives another alternative for making a nice bed floor. Stephen Denk of Buckner, Missouri came up with this process...

Between 1954 and 1959 the dash cluster of GMC trucks were given a circular opening for a dealer installed clock or tachometer. These trucks left the factory with a blank-out plate to fill this opening. With most GMC's this plate always remained in place as an option was rarely added. The enclosed photo shows both plates used during the period...

This fact about car and truck generators is not known to most.  We hope, you find this of interest. Both ends of most generators after the mid 1930’s had openings for air to pass through their internal moving parts.  The small fan on the front it is attached to a pulley that is turned by the belt reaching the harmonic...

For the true Advanced Design perfectionist, this GMC accessory should be of interest. SO RARE!Of the few bedroll reflectors that were added by the GMC dealers, very few have survived. Over the years as the pickup aged and was given more work duties, the reflectors were a target for improper backing. After all, it was a work truck hauling even...

After about 30 years of the horn being secured to the engine intake manifold, it was moved to the radiator core support in 1954. This was also the same year the 235 six cylinder engine was introduced in trucks. The actual body of the horn was used for the first time in 216 engine trucks in 1953. This horn used...

Just in case, you have an interest in the Advance Design original brake system, this might catch your attention. For ½ and ¾ tons, in the left corner of the cab floor, is the foot operated park brake. Here, the lever extends vertically up through the floor so the driver’s foot can lock the rear brakes when keeping the truck...

America rightfully looks to its basic industries for renewal of prosperity. Its colossal utilities are employing thousands of GMC trucks in the construction of giant power dams and in weaving a network of wire and pipelines that project electrical and gas services even to the remotest outposts. This is a job that must be done mostly on wheels! Typical is...

When you check your truck odometer for a replacement, note the gear taper that turns the five numbered mileage wheels on the odometer assembly. Some have straight gears and others tapered.  Each have 15 teeth. The rule on Chevrolet, GMC and other GM vehicles is as follows: If the odometer gear teeth are straight cut, the unit fits below the...

On rare occasion you will see a pickup that has a pair of original design front bumper guards installed on the rear bumper. Big Mistake! This is a recipe for tailgate damage. One slip of the hand while raising or lowering the gate will allow it to swing down until it hits these bumper guards. The result is evenly spaced...

Since the first inline six cylinder Chevrolet engines were introduced in 1929, they had been attached to the front cross member of the car and truck frame. There were no actual rear engine mounts. The engine was secured to the bellhousing at the rear which was attached to the frame rails. For the Chevrolet “car only” this changed in 1952...

With most local radiator repair shops now out of business (you can buy late model radiators for modern vehicles much less than repairing the originals) finding repairs for original brass radiators is very difficult. Shop repairing large commercial truck and farm tractor radiators still are needed but usually in only larger cities. If your older GM original truck radiator does...

During the 1947-55 series, the five window cab often referred to as the Deluxe cab, was available as an extra cost option. Their two corner windows helped in visibility especially when backing. Cabs made during the same year are identical except for these corner window options.  Some buyers in the southern states rejected this option.  They felt the corner windows...

 Accessories and Options 1937-50 Chevrolet / GMC Spare Tire Lock1954 GMC Bedside Roll Reflector1947-55 Pickup Rear Bumper Guards – Wrong!1947-55 Chevrolet / GMC Running Board Safety Treads1940-1953 Accessory GM Reflector1954 Chevrolet Grille GuardAn Inner-Line Oil Filter1953 Chevrolet Truck Accessory Hood Ornament Mystery1947 - 1948 Recirculator Heater1953 - 1955 Fresh Air Heater1954-1955 Chevrolet Truck Accessory Clock1954 - 1955 GMC Spring Wind...

If you really like learning about old Chevy truck six cylinder history, this article is for you. We recently visited Jerry’s Chevy Restorations in Polo, Missouri and noticed an interesting display on a side wall of his shop. Jerry has the complete series of Chevrolet “Stovebolt” six cylinder valve covers used on cars and trucks between 1937 and 1962. This...

WD-40 Who Knew?What is the Main Ingredient of WD-40?Before you read to the end, does anybody know what the main ingredient of WD-40? No Cheating WD-40 ~ Who knew! I had a neighbor who bought a new pickup. I got up very early one Sunday morning and saw that someone had spray painted red all around the sides of this...

Accurate front end alignment on any straight axle can be done in your home garage. Stop unnecessary tire wear and pulling side to side. This basic blue-print shows it all. It’s a no-brainer! The two small notches on each end of the alignment plate are a suggested place to secure your measuring tape. NOTE: Alignment plates can be made from...

The early GM ½ tons roll along relatively well on today’s highways considering the roads they were designed for 50 to 60 years ago. As highways became better Chevrolet and GMC added extra horse power six cylinder engines (each model had its own inline six cylinder) to satisfy the demands of many buyers. Even with this improvement the ½ tons...

This large grommet is so hidden, most owners have no idea it exists. It is exclusive to the 1947-55 (Advance Design) Suburban, panel truck and Canopy Express. Because the body is so much wider than a step side pickup the full add pipe must be longer. The body also has an inner as well as outer panel. The inner panel...

  For the many people that have not seen a gas tank baffle, this should be of interest. These are usually flat metal dividers welded inside a fuel tank. They slow the side to side movement of the fuel. Numerous openings between the welded dividers cause a slower movement of fuel. See Photo. Baffle Trivia! 1. All tanks in a...

A big mistake! We can think of no better example of mistakes in currently producing older Chevy / GMC truck parts than this offering of a reproduction shift knuckle that is described “for the 1947-53 GM ½ and ¾ ton”. NOT only are they currently advertised for the wrong year, but they continue to be sold in this way after...

With the introduction of Halogen headlights, night driving is a little safer due to more illumination. However, this improvement comes with a negative for those still using a generator for their electrical charging system. To get the extra lighting from Halogen bulbs, the available amperage should be about 60. This will come from an alternator systems which has a charging...

The famous 1947-55 Advance Design Trucks were so popular in the US that GM just could not let them go. Overseas factories used this basic US tooling for their version of the Advance Design trucks. This continued for many years after they had been discontinued on US assembly lines. Look at some of these trucks in other countries using GM’s...

General Motors wisdom had it correct. They waited about 2 years after the end of WWII before introducing a new truck body design in mid-year 1947. With the returning military from overseas the truck sales (and all other cars & trucks) with pre-war older designs were selling faster than the factories could produce them. GM continued with the same trucks...

A redesigned dash was placed in the 1954 GMC. It was totally changed from the 1947-53 dash which had been in place six years. Due to this new design there was a place to install the radio but not its speaker! The next best location for the speaker was in the headliner between the driver and passenger. The GM engineering...

  When the 1954 Chevrolet deluxe pickup was introduced (about two months into the production year) they came with a different design arm rest not used before. It wasn’t even found on the assembly line produced standard 1954-55 pickups! Because the door panels and painted interiors of this new deluxe cab had four color choices, GM realized they could not...

We found this nice view of a 1947-53 Chevrolet/GMC panel truck interior. It shows a rear view of the very rare optional passenger seat in its raised position. It was necessary to give this right seat an ability to tip up and forward so access to stored freight would be more accessible from the passenger door opening. Very ingenious by...

One of the more common reasons for slow engine turnover using an original six volt system is under size battery cables. Most of today's auto parts stores only stock the smaller diameter 12 volt design. Unknowing owners mistakenly replace their original worn cables with shiny new ones that are as much as half the diameter as needed. In Addition the...

Even the smallest vacuum leak on an internal combustion engine can prevent it operating to the level of its capability. No matter how well you rebuild the carburetor, adjust the timing, or clean the gas tank, the engine will continue to operate below what it should even with a small vacuum leak. On older engines a quick, easy way to...

Six volt horn without a factory relay doesn’t sound? If you use the original 6 volt system, you “cannot” use the gray plastic incased brush and contact that also slips into the steering wheel hub on the 1947-52 First series Chevrolet/GMC Trucks. It is continually advertised for the 6 or 12 volt system. This is made only for the 12...

About 15 years ago, Jim Carter Truck Parts, decided to reproduce the “real” GM step plates used in the years of 1947-55.  Though there were hundreds of step plate designs available during the early years, but only one is pure. The 1947-55 Chevrolet/GMC Running Board Safety Treads and was made available by the GM dealers. No lettering exists so they...

We assume the increase population of these little 12 to 15 pound rodents in the past 20 years is due to stricter in-city zoning that does not allow dogs outside without some type of restraint.Beware! Ground hogs (woodchuck) are on the hunt for a dry place out of the rain to call home. They love a dry dirt floor in...

This new Chevrolet Horn design was introduced in 1934. It is attached direct to the 207 six cylinder engine and was so successful there was almost no changes through 1952. As shown in these photos this 1934-36 Chevrolet Horn was attached to a flat foot that secured it to the center of the intake manifold. The long nose directs the...

The Korean War has ended and copper used in quality chrome plating is now readily available at an acceptable price to commercial buyers. General Motors loses no time introducing a deluxe pickup in both their Chevrolet and GMC lines. Quality chrome plating was required for this project and was now in stock. Other metals have also dropped in price including...

To add better night visibility to all Pickups, Big trucks, Suburban’s, and panel trucks, General Motors offered a 4 inch diameter 1940-1953 Accessory GM Reflector as a dealer installed accessory.  With the single small factory taillight, seeing of these vehicles on the road could be difficult especially if their one bulb burned out.  To help correct this problem GM offered a...

We recently had a local radiator repair shop clean the rust from an older used 1949-72 Chevrolet/GMC gas tank.  They submerged it in a cleaning acid tank overnight. The price was over $75.00.  WOW!  It was expensive! Several months later we discovered an “old school” method that is a very low cost. Oh well, we live and learn. Thus done as...

The first year of the Chevrolet pickup with a Hydramatic transmission was 1954.  Though it did not find a large percentage of buyers, this truck did open the door for an increasing number of this transmission in the coming years. When sitting in the 1954 Chevrolet truck cab with this new option, some changes are immediately noted. To operate the...

A nice dealer installed accessory in 1954 was the grille guard. It was easily installed by using the pre-existing bumper bolts. A problem when installed was that it lessened the visibility of the front license plate. Therefore, another change was made during the installation. The license was moved to the center of the front splash apron from the factory position...

One of the rarest Chevrolet dealer installed truck accessories of the 1950's.  Charles Callis of Union City, Tennessee recently found this original radiator cover that he installs for shows on his 1953 1/2 ton. Note the Chevrolet logo on the lower right side to prove it's the real thing! It is pictured in the 1949 Chevrolet Salesman's Data Book on...

What an unusual idea!  If you have clear coated your bedwood, replace the metal bed strips with dark stained wood. Of course, this is for a pickup not used for hauling, however as the owner said “If you clear coated your bedwood instead of painting it as original, you were not planning to work with it anyway”.

The full rear quarter panels for the 1947-55 Chevy/GMC Suburban were made all the same at the metal stamping manufacturer.  To save money these panels were not made different if the Suburban was to have the double doors or the tailgate style opening in the rear. Thus, when the Suburban was provided with a lift and tailgate combination the 4...

Attached are some pictures of the correct 1947-1955 GM panel truck seats. The right side was a factory option. This would be special ordered if the owner was planning on two passengers. Though they have been recovered with cloth instead of factory “leatherette”, they are correct in all other ways. What is interesting is how GM made the optional right...

What an ingenious way to keep a tail light in view! General Motors realized that with the tail gate in the lowered position the center tail light still had to be seen by the following traffic. At times the gate will stay lowered when longer freight is carried. Therefore, the 5” round light is attached to a swing bracket. This...

Leaving your truck, car, or most all gasoline operated equipment in storage is asking for trouble!  Many of us, as hobbyists, collect more cars and trucks than we will drive at least monthly.  They sit in the back of your garage or are stored across town in a friend’s garage, barn, etc. Three to five years later when it is...

We ask our readers: What is the correct color for the letters and numbers for the 1947-53 Chevrolet truck dash gauges? Were they white? Have they slightly yellowed after 50 years and now have a more cream color? Our company has made the decals both with white and slight yellow hue. We had assumed the originals have slightly yellowed with...

Surprise!  The well known GMC grilles from 1949 through early 1955 use the same bars.  This includes the more popular ½ ton through the very large over the road and quarry trucks.  Chrome or painted, the four horizontal stamped metal bars are identical.  Look at the following photos.  The grille bars interchange!

An Inner-Line oil filter from Long Island, New York!  Rarely seen today but a popular early aftermarket option.  It secures to the engine block after removing the oil distribution cover.  No oil lines.  No moving the horn forward to make room for the intake manifold mounted oil canister.

Rebuilt Speedometers for Chevy Trucks & GMC Trucks When your older truck needs a rebuilt speedometer, think of Jim Carter Truck Parts! Our company, in combination with a specialized shop, provides a quality product that you will be proud to place in your vehicle. With most new repair parts no longer available, we obtain used speedometers from across the country...

It is very unusual that we are asked to create a 1954-55 GMC gauge panel.  Our customer had lost his due to an un-professional rebuilder and was in a panic.  We finally were able to create this set after an involved hunt in our various storage locations.  What a job!  All needed complete rebuilding and appearance upgrading. We thought this should...

What a unique invention. When you have a 1947 through 1959 single rear wheel 3/4 or 1 ton GM truck and need more pulling power, this is the answer. American ingenuity at its best! This new steel center hub extension includes eight long bolts to reach the original wheel studs. This holds the factory wheel in place and then provides...

It is very important where to drill the hole for the new radio antenna. The results of making a slight mistake will stay in your mind for many years to come! Radios during these 1947-54 Advance Design years were never installed at the factory. This was done by the authorized GM Dealer. In the box that contained the new radio...

Article courtesy of Rob English (rob@oldgmctrucks.com) The issue of multiple piece rims and safety comes up frequently. There seems to be a quick rush to judgment about any rim that has more than one piece, and while certain types of multiple piece rims have indeed been outlawed and are no longer made, many others are not only still in service...

Ever wonder why GM pickup rear bumpers became an option for so many years? Jim Carter Truck Parts wanted to know also. Here are the facts:Beginning in 1951 these bumpers became an extra cost option and have remained this way for so many years on most pickup models. The reason relates to trucks being mostly for work. Though protecting the...

Purchasing a 1947-1953 optional cigarette lighter assembly from some vendors provides reproduction that is far from original in appearance. A manufacturer recently offered the optional lighter assembly but used a knob from the headlight of a 1947-1953. There is no similarity to the real lighter! Don't be embarrassed at a show where your vehicle is being judged. Reproduction (above) Image...

  Prices of more valuable metals such as copper and nickel reached their height during mid 1951 through 1953. Though U.S. shortages were much less than in WWII, there were price increases in the market that affected the financial bottom line of auto and truck manufacturers. America almost demanded chrome on cars even if it raised prices. Decorative shiny trim...

  As per GM, accessories during the 1930's through mid 1960's were the extra cost items sold and installed by the approved dealer. The truck was prepared for these during production so the dealership could later add them with less effort. As much as possible GM would punch holes, attach removable plates, press in dimples, etc. to help the dealership...

GM trucks titled prior to the mid-1950's were usually registered using the stamped engine number not the body digits pressed in the door ID plate. This practice has created many problems in later years as states became stricter in titling. Unfortunately, many older vehicles outlast their engine and owners rarely rebuild the originals. To save time and certainly expense, a...

To keep the 1947-1955 GM trucks base price low, their 6 volt cigarette lighter was a dealer accessory. The vehicle always came from the factory with a round blank out plug at the lower center of the dash.

In contrast to 1954-1955 Chevrolet trucks, the same year GMC had a position in the dash for an optional gauge. It was here that larger GMC's had a tachometer or vacuum gauge installed. The 1/2, 3/4 and 1 ton GMC's usually did not require these engine gauges and a blank-out plate is normally found there. An option here in these smaller trucks is a spring wind clock. It was produced by General Motors and installed at their GMC dealerships.

Jim Carter Truck Parts viewed so many older salvage yards to find so much of this data by accident! It was just there! There couldn't be an easier place for a tree to grow. If you don't move your truck for a few years, trees will find it. As they grow wider, the truck bends to fit! Here livestock cannot...

With the introduction of the Advance Design Cab in 1947, a new dealer installed heater also became available. When used together this new body was referred to as The Cab That Breathes.

By the mid 1950's extra income in the U.S. was creating an increased demand for accessories on both cars and trucks. To take advantage of this, the Chevrolet Truck Division introduced one item as a first. It would not appear again on Chevrolet trucks until the mid 1970's.

  It's surprising that an item placed on almost every 1947-55 Chevrolet and GMC truck has become so impossible to locate. Most collectors have never seen one! The product is the five inch GM round mirror head. It was originally bolted to the cowl mounted mirror arm on the driver's side. They were always black and had the pivot on...

The Chevrolet dealer installed recirculator heater was much different in 1947-48. In 1946 and older plus in 1949 through 1957, they sold the traditional round core design but for 1947 and 1948 it was all different.

  No less than three different mirror arms were used on Advance Design Trucks (1947-1955). Though most vendor catalogs do not reflect these differences, the following should be of interest to those that want their truck restored correctly. All left mirror arms attach to the same position on the cowl, however two designs were used. In the beginning years (1947-50...

  We often get requests for a formula to make the Advance Design pickups more freeway friendly. Their original ring and pinion gears were created to make the truck's six cylinder work well with a load and also keep up with the 1950's traffic on gravel roads and two lane paved highways. Though a higher speed reproduction ring and pinion...

</a > On the new 216 six cylinder engine, introduced in 1937, the vacuum advance was placed on Chevrolet trucks and cars at the right side of the engine below the distributor. A small metal vacuum line across the front of the engine connected to the carburetor base. This vacuum advance design continued on trucks through the end of this...

The Trials and Tribulations of Installing a GMC 302 engine into a 1950 3/4 ton Chevrolet Pick Up by Joel Baumbaugh   Background: About 5 years ago I "upgraded" the engine in my truck from a 216 to a 235. Lately I have felt that I wanted/needed a little more torque (especially while the bed is full of something heavy...

  During the Advance Design Truck years, two air filters were available when an order was sent to the factory. The base air filter (no extra cost) was the oil-wetted design from earlier years. The owner was expected to place a thin layer of motor oil on the filter media. Dirt particles would be caught by the oil as it...

By January 1949 GM realized there was an engine noise in the new late 1947 Advance Design cabs that needed correction. If a truck customer complained, the dealer was given a solution by modifying a part from a Chevrolet car. The problem was engine noise entering the cab through the horizontal accelerator rod where it touched the floor hole. On...

  Between 1954-1962, Chevrolet produced their famous full oil pressure 235 cubic inch six cylinder in trucks and it soon proved to be one of the greats among engines. However, at the same time a lesser known "big brother" to this base engine was being used. This was the quality built 261 cubic inch six cylinder! The 261 was available...

And now we've seen it all! A real example of American ingenuity. Designed by an aftermarket company to keep an over tightened valve cover from leaking motor oil down the engine sides.  A metal band is pushed over and around the base of the valve cover.  Brass U-brackets are then secured by the two valve cover studs.  This creates equal...

Chevrolet introduced their basic nine inch single disc clutch and corresponding diaphragm pressure plate in 1938. This pair was used in their cars and most 1/2 ton pickups with three speed transmissions through 1953. With about one million of these vehicles sold annually, one can quickly realize the high numbers of this clutch system that was at one time on...

The door window is cranked up tight in the cloth channel and off you go on your daily errands. Suddenly, the glass begins to slowly lower as you drive over side roads or contact a rough surface. In comes cold air, rain, and wind! Even the window handle turns. What's this all about? Do you tape the window closed or...

  During the 1940's through 1950's placing pin stripes on automobile wheels occurred on most all brands. It was an inexpensive touch that added a little flair to the appearance of a new wheel. The stripe could be added quickly with a machine on a rotating wheel. The factory didn't need a human as on the body stripes. GM was...

Before the modern Positive Crankcase Ventilating System (PCV) most automotive engines breathed externally and removed their excess products of combustion into the atmosphere. It was a standard of the industry! The lower end of the engine (below the piston rings) had an attached draft tube that extended outside and below the block. It released blow-by from worn piston rings and...

Sometimes overlooked by mechanics and restorers is a small vent in the rear axle housing. This part is necessary to keep internal pressure equal to the outside atmosphere. Thus, as the internal temperature of the differential warms during use, any expanding heated air is vented and no pressure occurs. This saves wheel and pinion seals from leaking. Check for this...

One series of the famous "drop out" GM differentials was used between 1946 and 1972 on 3/4 and 1 tons. The complete assembly (often called a pumpkin) will interchange during these years with no alteration. The highest gearing in this series is the 4.10 ratio and is found in most 1967-72 3/4 tons with automatic transmissions. Therefore, those "low gear...

With the introduction of the Advance Design panel truck in mid 1947, it was soon evident that a serious safety hazard existed with a few companies, some night deliveries required the rear double doors to be open. This prevented the taillight from being seen! No doubt this caused some accidents particularly with a fast vehicle coming from behind, with dim...

  Beginning in 1951, the rear bumper became an option on both Chevrolet and GMC pickups. This required a change in the standard left tail light bracket. The tail light assembly was now unprotected without the bumper. GM created a new bracket design that brought the tail light slightly ahead of the rear edge of the stake pocket. In this...

  The Chevrolet and GMC left commercial taillight used during 1947-1953 is an excellent example of GM's conservative thinking towards trucks. The number one purpose for trucks was work! Therefore, if a part had been very successful on a prior body design, it just might be adapted later as a part in some new styling. Savings were in production costs...

A redesigned parklight assembly was started with the introduction of the 1947 GMC advanced body style. It was placed in the front fender 3-1/2 inches below the headlight ring. A 2-5/8 inch diameter bezel held a domed glass lens to its housing by two barrel screws. The unit was not meant to be a combination turn signal and parklight assembly...

  When viewing older GM cars and trucks we see both colors of park light lenses. There seems to be no consistency that gives us the proof of what is actually correct, however, it is easy as remembering a year. Beginning in 1963, the Department of Transportation new federal regulations required park lights to show an amber color, to be...

Four Speed Backup Light Switch - They Did Exist! The first design of the 4-speed synchronized truck transmission, introduced in 1948, was used through about 1965. About mid series, when the dealer installed backup light increased in popularity, a special switch was attached to the base of the floor shift lever. This was the only location possible as there is...

  When observing restored 1947-1953 Advanced Design trucks, we rarely see the removable dash parts painted correctly. Though at least half the owners paint these parts to their personal taste, many truck restorers want the dash appearance as original. Surprisingly, we rarely see two alike even on trucks that are said to be restored just like they left the factory...

Between 1954 and 1959 the dash cluster of GMC trucks were given a circular opening for a dealer installed clock or tachometer. These trucks left the factory with a blank-out plate to fill this opening. With most GMC's this plate always remained in place as an option was rarely added. The enclosed photo shows both plates used during the period...

  Among the many updates in the new Advance Design body style in 1947, one that certainly stands out, is the change in gas tank positioning. For the first time since 1936 it was placed outside the cab and under the bed. The dimensions of this 16 gallon tank were based on the limited space between the right frame-rail and...

What's this bad rap some people give the GM pickups with in-cab gas tanks? For 35 years GM protected these tanks from collisions by double wall reinforced cab metal, doors, and seat riser frames. The 1937-46 pickups even secured the tank under the seat and surrounded it on three sides by the welded to floor heavy gauge metal seat riser...

  To help prevent metal to metal contact when 1/2 and 3/4 tons are overloaded or have weak shock absorbers, truck manufacturers used a rubber devise. This cushion prevents the axle from making direct contact with the frame rails. On the rear of the 1947-1953 GM pickups, it attaches directly to the underside of the hump in the frame. It...