and entire websites are dedicated to the problem. Should you have any concern about the issue with your own project, you have a few options.
First, you can purchase a fuel cell. Aftermarket fuel cells come in all shapes and sizes, and have increased safety standards, depending on where you purchase them.
You can purchase a plastic foam-filled tank made to meet NHRA specifications and mount it between the frame rails just behind the axle.
You can purchase a gas tank from a Chevrolet Blazer or GMC Jimmy of the era, which also mounts behind the axle between the frame rails. You have to change some plumbing and wiring, but it at least has a factory appearance, even if it’s not in the stock location.
Finally, you can always leave it the way it is. If you’re not planning on driving the truck very often, your risk of injury is less. Plus, even if you do drive the truck every day, the chances of you being hit in the same manner that would cause the tank to puncture is minimal, so keep that in mind.
Whatever you chose to do, just be aware of the problem so that you can address it if necessary.
Overview of the 1973–1987 Chevrolet Pickup
Although the 1973–1987 Chevrolet pickup had the longest run of any line of Chevy trucks to date, some purists divide the generation into two distinct groups: 1973–1980 and 1981–1987. If you want to get technical, the Suburbans, duallys, Blazers, and crew cabs were available until 1991, creating, essentially, a third generation, depending on how you look at things.
Chevrolet first referred to them as the “Rounded Line” of trucks, but today enthusiasts often call them a “Squarebody.” To most people, it’s the most square of the current and past body styles.
Body Style Changes
The 1973 model received the “Rounded Line” moniker because almost every corner or angle on the truck had a rounded edge. For example, the windshields had rounded corners, as did the windows and front fenders. The taillights also wrapped around the bed sides, which was the first time that was done on any Chevy truck.
The purpose of the Rounded Line was to increase fuel efficiency by using aerodynamics. The bed sides also featured a double-wall construction, which, in some earlier years, also produced some rust complaints because water pooled between the two walls of the bed, causing rust. Keep an eye out for truck beds with poorly patched panels.
Three bed models were available at first. The Wideside (also called the Fleetside model) came in a short or long bed; the Stepside (called Fenderside by GMC) also came in a short or long bed; and the “Big Dooley” (now referred to as a “dually”), which was a long Fleetside bed with fenders on the outsides to accommodate the dual rear wheels on the 1-ton trucks. The Stepside/Fenderside also came standard with wood floors, which were replaced by metal floors in 1980.
The body style went through a major change in 1973 and again in 1981, as was the case with this later-model example.
The cabs came in two choices: standard and crew cab. The latter had two versions: a “bonus cab” that had no rear seat and included a lockable storage compartment instead, and a “3+3” that had bench seats front and rear.
Because of these new cab and bed sizes, three wheelbases were offered for the trucks: 117½ inches for the standard-cab/short-bed pickups, 131½ for the standard-cab/long-bed trucks, and 164½ inches for the crew-cab/long-bed (or Big Dooley).
Other variants of the truck also use the same chassis, including the Custom Deluxe with camper, Blazer/Jimmy, and Suburban.
The Squarebody evolved substantially over its 14-year model run, and I’ve highlighted most of the major changes below. This will help you find the truck that best fits your needs.
1973
Compared to the previous 1967–1972 trucks, this first year of the body style had 21 percent more glass area, an optional radio antenna embedded in the glass, and a bigger cab. Front disc brakes became standard, and the entire suspension was beefed up to go along with Chevrolet’s motto, “Built to Stay Tough.” The crew cab was also introduced this year. As for the engine, this was the last year that you could buy the 307 V-8; the 402 big-block available in previous years was now replaced with the 454. There was also an inline 250- and 292-ci 6-cylinder as well as the 350-ci V-8. If you want a two-tone paint job, your second color option is white, and only white.
1974
The exterior of the truck was mostly the same, except that rain gutters became available for the areas around the side windows. Both 1973 and 1974 shared a grille commonly referred to as the recessed “egg crate” grille, named for its appearance.
1975
Higher trim levels (discussed below) came with aluminum panels on the tailgate, filling in the typically recessed area. Rain gutters were now standard on all trucks, as was a modified tailgate latch mechanism on Fleetside beds. The Scottsdale trim level was introduced. On the inside of the truck, the windshield wiper switch was modified slightly, which changed the bezels found in the 1973s and 1974s. HEI ignitions were now standard, as were catalytic converters. The front grille now featured three horizontal bars, which also eliminated the recessed feature of the previous years. This was the last year that you could find out the displacement of the engine based on the badge on the grille.
1976
Because of rust issues, General Motors added more zinc to its primer. Buyers could purchase chrome bumpers with rubber impact strips, plus they could select Rally wheels and/or a Sport model. You could now order a two-tone vehicle with a color other than white, and the Bonanza trim option was introduced. This was also the last year that the engine block was orange.
1977
Power options were available for the first time, including intermittent wipers, power windows, and power door locks. The door panels and door internal components were also different from previous years. Bucket seats came in two variations: early models had low backs and later models had high backs; it depended on when in the model year the truck was built. An inside hood release became an option and the grille changed one of the horizontal bars and four of the vertical bars were removed. A yellow/gold stripe was an option for the center of the moldings, and, other than the 1975 GMC Gentleman Jim Special Edition, this was the only year it was an option. General Motors introduced the 305 V-8, and a rear defroster also became optional.
1978
A 350 diesel engine became optional in 1/2-ton trucks. The frame was tweaked slightly to fit catalytic converters, which were now required on California trucks. This also meant that California trucks did not have a dual exhaust option available. Brushed-aluminum trim became standard on the top trim levels, replacing the wood grain. The bed received a gas door, rather than the
