On GMC’s Pickups with Diesel Power sales sheet, a red-and-white pickup fills the front, with an engine photograph above it and five smaller pictures below. Look a little closer and those smaller pictures tell you where GMC wants the conversation to go: batteries, dashboard lights, an injection pump, brake assist and glow plugs. There’s more to explain here than a different engine under the hood.[1]
Pick your body and box
Turn the sheet over and the choices are easy to follow. The availability chart lists C-1500 pickups in both Fenderside and Wideside form. Either body comes with a 117.5-inch wheelbase and nominal 6½-foot box, or a 131.5-inch wheelbase and 8-foot box.[2]
There’s a small detail worth catching if you’re using this sheet to research a truck. GMC repeats TC-10703 for the shorter combination and TC-10903 for the longer one under both body styles. On this particular chart, the code alone won’t tell you whether you’re looking at a Fenderside or a Wideside. You need the body column, too. And these are the choices on this sheet, rather than a list covering every GMC or Chevrolet truck.[2]
What GMC put on paper
The engine is a 5.7-litre, 350-cubic-inch V8 diesel. GMC’s table lists 120 net horsepower at 3,600 rpm and 220 lb-ft of net torque at 1,600 rpm.[2]
Fuel economy is part of the pitch, alongside explanations of the rotary injection pump and electric glow-plug starting system. There’s no measured fuel-economy result in the material reviewed here, though. We can read what GMC wanted buyers to know without treating the sales sheet as a promise of what an old truck will deliver today.[1][2]
What came with the diesel?
Ordering the diesel in one of the listed C-1500 Wideside or Fenderside pickups brought quite a bit of equipment with it. The sheet includes an automatic transmission, power steering, and Sierra interior and exterior trim. It also lists an engine oil cooler, block heater, two batteries, dashboard glow-plug and start lights, and insulation in several areas of the cab.[2]
That helps make sense of the little photographs on the front. GMC was showing buyers some of the equipment that went along with diesel power. But there’s a trim detail to watch: the captions identify available High Sierra trim in the engine-compartment and instrument-cluster views. Sierra is what the sheet lists as standard with the diesel; those pictures don’t change that.[1][2]
If you’re comparing a truck with this sheet, start with the body, wheelbase and equipment you can document. The photographs are useful for understanding the offering, but they can’t settle how an individual truck left the factory.
A note on the date
AutoPaper catalogs this sheet as 1978. We haven’t established an independently printed issue date or an explicit model-year statement from the photographs, so the title here stays undated. The sheet carries Form ADV 78-19, but that number isn’t being used as proof of a date. The details above apply to the C-1500 pickups covered by this sheet.[3]
Sources
- GMC Truck & Coach Division, General Motors Corporation, Pickups with Diesel Power, Form ADV 78-19, undated, unnumbered front. AutoPaper source photograph: Front source photograph
- Same sheet, unnumbered reverse, headed Diesel Power for GMC Pickups: Reverse source photograph
- AutoPaper, seller listing, “1978 GMC Pickups with Diesel Power Engine C1500 Sales Data Sheet Original”: Seller’s listing
