My New Truck....What Do I Have?

[Fraser Beatty]

Well I bought a "new" truck today, and man is it a beater. It is badly rusted and the interior is absolutely wrecked, but it runs great with a rebuilt 350. And, in my area, it was a good deal at $500 Canadian. I am a little confused as to what I bought, though. The owner told me and was convinced it is a 1979 Chevrolet 3/4 ton, however, it appears to be a GMC 1/2 ton with heavy duty options. The VIN is TCS3491548762, which confirms that it is a GMC (first digit), 2WD (second digit), pick-up body type (fifth digit), year 1979 (sixth digit), and made in Canada at the Oshawa plant (seventh digit). What I can't understand are the third and fourth digits, S and 3. The S is supposed to indicate the engine size and type, but by my VIN decoder shows it should be a D,L,R, or T. The 3 is supposed to indicate whether the truck is a 1/2 ton, 3/4 ton, 1 ton, or heavy 1/2 ton. Since it is a 3, that would indicate the truck is a 1 ton, WHICH IT IS NOT. I think it must be the GMC version of the Chevrolet "Big Ten", but I am just not sure. I will try to post pictures of the truck below. Anybody know what I have?