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?

[vern350]

not sure if I can help you out with your problem, but just wanted to say Hi. I'm also from sarnia area; camlachie.

[Fraser Beatty]

Here's an attempt at some pics....by the way the trim says Sierra Classic GMC 35.

[Fraser Beatty]

Hey there vern 350, I am up here on London Line between Brigden and Waterworks Sideroads. Next time you head into Sarnia on London Line you will likely see the truck in question sitting out in our driveway, alongside my Dad's 1985 GMC.

[vern350]

i know exactly where you are. Nice to see someone local on here. Truck looks like a good work horse.

[Fraser Beatty]

It's really beat up and rusty, and its got a ridiculous amount of kms, over 850 000! But I figured I can use it as a farm truck and to learn body work on (I've restored tractors before but never a truck). And the 350 engine can be used in my Dad's truck if worse comes to worse. So, anyone know what I have?

[vern350]

This is what i got....

T-GMC
C- 2 wheel drive
S-454-4
3- 30-one ton
4-pickup
9-1979
1-oshawa

[Fraser Beatty]

Okay that is pretty much what I got...The only problem is that darn 3.....the truck is clearly not a one ton, even though the VIN indicates that it is. Another thing that confuses me is the trim that says "GMC 35". I have never seen nor heard of this model designation before.

[1974ChevyC10]

Originally Posted by Fraser Beatty

Okay that is pretty much what I got...The only problem is that darn 3.....the truck is clearly not a one ton, even though the VIN indicates that it is. Another thing that confuses me is the trim that says "GMC 35". I have never seen nor heard of this model designation before.

ok ill try to break this down a little more.i dont know alot about canadian trucks and there vin's since im from the states but here goes.it looks like it could be a 3/4 or 1 ton single wheel the gmc 35 means a 1 ton.at least in the states a C10 is a chevy 1/2 ton,C20 is a chevy 3/4 ton,C30 is a chevy 1 ton these are the two wheel drive versions,G15 is a GMC 1/2 ton,G25 is a GMC 3/4 ton,G35 is a GMC 1 ton also the two wheel drive versions.add a K in front of those numbers and you get the 4x4 designation.hope that somewhat clears it up for ya

[xtreme80]

According to LMC's vin decoder, it is in fact a 1 ton

http://lmctruck.com/icatalog/cc/0012.asp

[Fraser Beatty]

I am beginning to think that I have the GMC version of the Chevrolet "Big 10", since the truck appears to be a 1/2 ton with 3/4 ton springs, HD shocks, and HD brakes. Either that or the original owner of the truck ordered it from the factory with lots of extra options. But there are still some things that just do not line up. Why does the truck have a 3 in the VIN, indicating it is a 1 ton, when it clearly is not a 1 ton? And what the heck is GMC 35 supposed to stand for? I have attached a pic of the VIN, a pic of the GMC 35 trim, and a pic of the heavy duty springs below. Another interesting piece of information is that the truck has factory AC, which is not working, as someone removed parts of the system. Anyone know what I have????

[xtreme80]

Also, what makes you think it's NOT a 1 ton? Should have 8 lug wheels right?

I just don't understand your reasoning behind it not being a 1 ton?

EDIT: The 35 is GMC's version of a C30, which is the chevy. Instead of a CK30, you have a CK35, which was GMC's version. Same truck, different number.

Also, try to get some pics of the front and rear suspension if you can. I don't personally know what a 1 ton will look like, but I'm sure someone on here will.

[Fraser Beatty]

1974 ChevyC10: I knew that before, about the relation between Chevy and GMC model designations, I just hadn't realized that GMC used to call them G15, G25, and G35. They must have switched over to calling them 1500, 2500, and 3500 in the 80's. Guess you learn something new everyday.

xtreme 80: Yes, it does have 8 lug wheels. I know that according to the VIN it should be a 1 ton, but it just does not seem to be a 1 ton size-wise. Side-by-side with my Dad's 85 GMC C1500, they appear the same in terms of size and the way they sit on level ground. I have seen both 2WD and 4WD 3/4 tons and 1 tons before side-by-side with my Dad's truck, and they always seem like they sit higher. However, I have never before seen a 1 ton single-rear-wheel 2WD truck, so you may very well be right. I certainly would not mind if my truck were a 1 ton

['83Sierra]

35 means 1 ton. I dont see why it cant be a 1 ton?

[BLE 'BURBAN]

10,15,1500 All = 1/2 Ton
20,25.2500 All = 3/4 Ton
30,35,3500 All = 1 Ton
C('73-'87) = 2 Wheel Drive
K('73-'87) = 4 Wheel Drive
And On '88-'91 Blazers, Crew Cabs & Suburbans
R('88-'91) = 2 Wheel Drive
V('88-'91) = 4 Wheel Drive

[Pyrotechnic]

It has 8 lug wheels.

8 lug wheels = 3/4 or 1 ton

It DOES NOT have to be a dually to be a 1 ton. They were offered in a single rear wheel configuration with a lower GVWR.

Also, it doesn't look like your rear spring pack is stock. It looks like someone took some of the leafs out. Not uncommon since 3/4 and 1 ton springs give a really harsh ride. The truck has been around a long time at this point - plenty of time for people to have messed with it, so don't treat it as show room original.

[Fraser Beatty]

The only reason I was doubtful was because the guy I bought it from was convinced it was a 3/4 ton, and the truck just didn't seem at first glance to be a 1 ton. Also the S in the VIN did not line up, since I searched and searched and could not find what the S stood for. I though that maybe the S when combined with the 3 was some sort of special designation. However, I guess since all evidence points to it being a 1 ton, it must be. Like I said before, I don't mind at all that it is a 1 ton. I plan to fix it up and use it as a learning tool. As I mentioned previously, I have restored tractors and worked on trucks doing minor stuff before, but I have never tried to tackle something this major. The truck has a good running 350 that was rebuilt not too long ago, but thats about the only positive feature. The floors in the cab are rusted through, and the bed isn't in the greatest shape. The interior is in terrible shape, with a badly torn seat, cracked dash, etc. The heat and AC don't work. The speedometer does not work properly (it reads about 10km/h too high). For some reason I immediately loved the truck though, and I know it will be a great learning experience and worthwhile project. Maybe I am crazy??????

[Fraser Beatty]

Thanks to all who have helped me determine what I have...I will keep you updated as I dive into this project.....

[vern350]

glad to see you got things some what figured out. Let me know if you need any parts, i've got a few trucks around.

[Fraser Beatty]

Well, I have got things figured out now...Guess what I found? I took a look behind the seat, and I found the original sticker off of the glove box back there, along with 2 fairly new Sony XPLOD speakers, which were unhooked. Double bonus! The sticker proves that the truck is, indeed, a 1 ton, that it originally came with a 454, and that it is a "camper special". I am now wondering if the truck might still have a 454 in it, since the guy I bought it from was wrong about it being a 3/4 ton, he may very well have been wrong about it having a 350. I am no expert on engines, so can anyone tell me how to tell the difference between a 350 and a 454? I tried looking for any numbers on the engine that could be used to I.D. it. All I could find in the dark with a weak flashlight was the number 18436672 stamped on top just under the air cleaner assembly. Not sure if this is of any help to anyone in identifying the engine, but I though I would post it anyway. Thanks for all the help everyone.

vern350: Thanks, I have a feeling I am going to be searching around for A LOT of parts for this project. I will definately keep you in mind. My e-mail address is FBeatty_09@hotmail.com, if you could send me your e-mail address and maybe phone number than I would be better able to get ahold of you. Thanks for your help.

[1984Silverado4x4]

Originally Posted by Fraser Beatty

All I could find in the dark with a weak flashlight was the number 18436672 stamped on top just under the air cleaner assembly.

The number 18436572 stamped under the air cleaner is the firing order.

The engine ID number should be on the drivers side of the engine back by the bell housing.

[Fraser Beatty]

Ooops, guess I shoulda realized that when I wrote it down....told ya I was no engine expert I am goin out right now with a better flashlight to look for the engine ID number.

[Fraser Beatty]

Hmmm...I couldn't find the engine ID number, maybe I will have better luck with a longer search in daylight...I did, however, snap a couple of quick pics of the engine. Maybe someone can ID the engine from the pics, or circle the area I should be looking in for the ID number. Thanks.

[ElGracho]

Well, it's not a 454. The valve covers on a big block are an easy way to identify them vs a small block.

It's most likely a 350 since they are the most common small blocks and still one of the most common engines on the planet.

[Fraser Beatty]

OK....I was holding out hope the guy who sold it to me was wrong again and it still had a 454 in it.....Oh well....