The Stovebolt Site Forums The Shop Area General Truck Talk Gmc vs chevy advance design

Which was considered "better" the gmc model or chevrolet?

First thing to get straight : truck-series names:
Chevrolet Advance-Design trucks
GMC New Design trucks
Mid/early-year 1947 through mid/early-year 1955

Chevrolet sold 1/2 ton through 2 ton trucks
GMC sold trucks from 1/2 ton though much larger than 2-ton trucks

In 1955, the series names changed to:
Chevrolet Task Force trucks
GMC Blue Chip trucks

The main mechanical differences were in the engines/radiators, and in the grills (and, in the wheels).
Chevrolet 216/235/261
GMC 228/248/302 (in small trucks)
In 1954, there were significantly different interior dash board and gauges.

GMC engines were considered to be better, for several reasons:
- better/harder casting metal
- better carburetors
- other ??

Thanks for the soda by side comparison TC..... that is very helpful.

Was one more expensive than the other and thus considered "premium"?

Also, would a gmc be considered as more desirable in the restoration world?

" Was one more expensive than the other and thus considered "premium"? "
GMC was probably more expensive.
GMC was probably thought of as "more premium"

" Also, would a gmc be considered as more desirable in the restoration world? "
Hmmmm .....
I am not going to touch that one.

Ha!...... probably a smart move. We might crash the website.

Just some background, my buddy just bought an identical suburban to mine except his is a gmc. Just trying to get my info straight so I dont sound like an idiot in casual conversation.

I recently was up at a place picking up some parts on a craigslist, this guy sells lots of 47-55 stuff. A guy was just buying a seat for a pickup and I helped carry out the bottom section. Noticed it had twice as many springs in it as my 53 Chev 3100. He said it was a GMC seat thats why. Apparently the same exterior dimension but the insides are built better.

I just saw a movie documentary on the Korean conflict and there were many CCKW duece and a 1/2s. Showed them travelling down snow ridden trails in minus temperatures. They hadn't made that model since the end of WWII but there it was still working hard for our freedom. Give your buddy and his GMC all the respect it deserves IMHO.

True.....

I'm looking forward to pulling into car shows as a suburban school bus fleet! Should be an interesting sight to see!

Also might add that batteries are connected differently; gmc is positive ground, Chevy is negative ground.

Yes, good info, papas52

Which type of ground is better, and why?
(this should be interesting)

Negative ground obviously because that's the way it's supposed to be

Well, remember YOU started this; haha. For a magnet, the field leaves the negative side, travels through the air and enters the positive side of the magnet to form a magnetic field. GMC thought following this naturally occurring feat would work better in a battery circuit to give a hotter and more reliable starting corcuit, thus the positive ground for the return.

Negative ground became the norm in most vehicles in the fifties with the introduction of the transistor which requires a specific current flow direction. I believe that to be somewhere around 1955.

That is why British Lucas auto electronics have such a good reputation?

Ha! Yes I fought Lucas stuff on an old triumph motorcycle I had when I was 16. Lucas wiring is .......challenging.

Lucas made a lot of stuff!
The only thing that didn't suck, was their Vacuum cleaners.


Don

Did those "Lucas" vehicles get their grounds through the frame, or did they have negative hot wires and positive ground wires?

GMC frames were heavier gauge steel than Chevy frames.

I will give my two cents on this thread since I'm a GMC guy. I think a lot of good statements were mentioned above. I feel from just talking to people at shows and what not that GMC's are actually less desirable as a restoration project. The reason is simply it's easier to find parts for the Chevy trucks than the GMC trucks. However, owning several GMC's myself, you learn to know and meet people and where to find parts. I prefer GMC's because there are just fewer of them. You go to truck shows and you see Chevy AD trucks everywhere, but you have to look somewhat hard to find a GMC , and when you do, you have to go look at it. I think both makes of this style of truck were good trucks in their day and probably the most popular truck today that GM ever made. I do feel the GMC's were built "stronger", but they were also tailored to the farms and ranches and more so as an every day working truck where as Chevy marketed their truck for the more suburban type customer. Today, I don't really think that matters at all just due to how we are using these trucks(as show vehicles). It really comes down to personal preference and what kind of deal you get when purchasing. Some people like the looks of the Chevy grilles better where others like the looks of a GMC grille better. Anyway you look at it, it's great to see both makes at these truck at shows and on the road! Keep building them!!!!!

The BIG other feature on engines...........The GMC engines were insert bearing with full pressure lubrication.

Nice post, Skeet

Supposedly GMC 6 cylinder engines last longer than Chevrolet 6 engines, because the GMCs are harder due to a higher nickel content?

Yes the GMC grills were "bulkier", and the 54/55 Z-series grill was a monster/monstrosity. I admire that ugly grill on my Z-series GMC COE.

The GMC carburetors were/are far superior to Chevrolet Rochesters

Regarding lubrication, yes, GMC engines had high-pressure engines before Chevrolet changed in 1954. However, the 1958 Chevrolet 261 had a full-flow oil filtration system before GMCs.

I know we're talking about 47-55 trucks, but I think if you go back to the 30s GMC used engines from some of GM's car divisions, such as Pontiac L-head sixes. Maybe others. Do we have any 30s GMCs in the Gallery? I will research that.
I guess oldgmctrucks.com would have info like that. (I used to frequent that forum, but frankly, it's not particularly user friendly.)

I'll never forget what I heard was the difference between GMC, and Chevy from when I was a little kid. A GMC was just a Chevy with lock washers!

Canadian light duty GMCs had Chevy engines.

I did notice star lock washers on the inner fender-to-fender bolts on a pristine GMC 3600. Chevrolet's don't have them.

Having disassembled many of both, I've found Chevy had rivets, in a lot of places, whereas the GMC's had bolts.

GMC's took over some Buick 6 cyl. engines when Buick went to 8's.

Ed