Just For Fun... GMC vs CHEVY

[CaliDude76]

Im sure this has been asked before.. but I'm curious about whats the real difference between the GMC and Chevy's... besides some trim and grilles... I've heard that GMC's we're built a bit more tougher than Chevy's... any expert opinions out there??

[JohnC]

Originally Posted by CaliDude76

Im sure this has been asked before.. but I'm curious about whats the real difference between the GMC and Chevy's... besides some trim and grilles... I've heard that GMC's we're built a bit more tougher than Chevy's... any expert opinions out there??

Nope that's pretty much it...trim, and grilles. Other than that they are pretty much the same.

[Keith Seymore]

Originally Posted by JohnC

Nope that's pretty much it...trim, and grilles. Other than that they are pretty much the same.

They went down the same assembly line, one right after another.

(In fact, sometimes the same truck was a Chevy on one side and a GMC on the other!).

K

[CaliDude76]

Originally Posted by Keith Seymore

They went down the same assembly line, one right after another.

(In fact, sometimes the same truck was a Chevy on one side and a GMC on the other!).

K

Hey Mr Seymore, been reading some of your assembly line stories.. pretty kool stuff. Just curious though... I'm assuming not all of the trucks were specifically ordered by customers... but how did G.M. determine how many, and what trim packages to make (Silverado's, Sierra Classics, Custom Deluxe...and such..). There had to be hundreds of configurations on these trucks....

[Keith Seymore]

Originally Posted by CaliDude76

Hey Mr Seymore, been reading some of your assembly line stories.. pretty kool stuff. Just curious though... I'm assuming not all of the trucks were specifically ordered by customers... but how did G.M. determine how many, and what trim packages to make (Silverado's, Sierra Classics, Custom Deluxe...and such..). There had to be hundreds of configurations on these trucks....

Thank you; trucks that were not specifically ordered by customers were ordered by the dealers themselves, for their inventory or to sit on their lot. As such, GM didn't really care how many of any particular combination were made, just as long as they all got sold!

(This was in the days before CAFE ratings, and swapping vehicle sales around to try to maximize corporate fleet fuel economy numbers).

The combinations were almost infinite. In order to do Powertrain calibration, emissions and noise "pass by" testing we had to make sure every engine, trans and axle combination was covered and accounted for.

By the time you took into consideration: series (1/2, 3/4 or 1 ton), wheelbase (short, long and cab chassis), 2 vs 4wd, engine, trans, rear axle and tire options the combinations were in the tens of thousands...

K

[CaliDude76]

Originally Posted by Keith Seymore

Thank you; trucks that were not specifically ordered by customers were ordered by the dealers themselves, for their inventory or to sit on their lot. As such, GM didn't really care how many of any particular combination were made, just as long as they all got sold!

(This was in the days before CAFE ratings, and swapping vehicle sales around to try to maximize corporate fleet fuel economy numbers).

The combinations were almost infinite. In order to do Powertrain calibration, emissions and noise "pass by" testing we had to make sure every engine, trans and axle combination was covered and accounted for.

By the time you took into consideration: series (1/2, 3/4 or 1 ton), wheelbase (short, long and cab chassis), 2 vs 4wd, engine, trans, rear axle and tire options the combinations were in the tens of thousands...

K

Right On!... Thanks Keith, for the info. It's pretty awesome of ya to share your knowledge with the rest of the class!! I'm pretty sure I can speak for quite a few on this site... that it's greatly appreciated!

[dammitmitchell]

GMC
Godly
Man
Charriot..
heheheh

[BigBlocksRule]

Not in the old days - '72 and prior. GMC was the better of the two. They had more creature comforts and generally got stronger engines/trannies. Cabs, fenders and grills were all different on the '47 - '54's and some parts of the '55 - '59. There were several engines that were exclusive to GMC, couldn't get 'em in a Chevy. After '73, the only differences were the badging.

[STOCKISH]

A GMC is basically a Chevrolet with lock washers!

[wedgemon]

Originally Posted by 1972SuperCheyenne

A GMC is basically a Chevrolet with lock washers!

My Dad used to tell me that!

[GMC Guy]

Originally Posted by 1972SuperCheyenne

A GMC is basically a Chevrolet with lock washers!

haha i like that!

[CaliDude76]

Originally Posted by 1972SuperCheyenne

A GMC is basically a Chevrolet with lock washers!

I LIKE that black Chevy you got there!!! That's real clean, my friend. That's the look I'm trying to go for with the front and trim. I have painted rally's on mine... but diggin on the rims and wheels.. what are those rims?

[CaliDude76]

Originally Posted by 1972SuperCheyenne

A GMC is basically a Chevrolet with lock washers!

another question.... how hard was it to do that conversion? Can I get away with not draining my radiator, and A/C condensor.. to put the radiator support in? also.. is that the stock size air-dam? THANKS

[C-10 simplex]

i think the interesting thing was that GMC had their own 60 degree v-6 engine prior to 73ish; This was, i think, the first v-6 in a domestic brand---305, 351, 401, 478 etc.


1) This engine was gradually, around 68ish or something, then completely replaced by the chevy straight 6 in the gmc line.

a) Why was this? Was it because the staight six was the better engine? Or just cheaper?

2) The straight six was, in turn, replaced by the 90degree v-6---basically a small block minus 2 cylinders.

a) Why was this? Is the v-6 better than the straight six in light truck applications?

b) Even today, this v-6 is the basic engine for bare bones/stripper new silverados/sierras; i don't think you can get a straight six in a new gm pickup.

[Keith Seymore]

Originally Posted by C-10 simplex

i think the interesting thing was that GMC had their own 60 degree v-6 engine prior to 73ish; This was, i think, the first v-6 in a domestic brand---305, 351, 401, 478 etc.


1) This engine was gradually, around 68ish or something, then completely replaced by the chevy straight 6 in the gmc line.

a) Why was this? Was it because the staight six was the better engine? Or just cheaper?

2) The straight six was, in turn, replaced by the 90degree v-6---basically a small block minus 2 cylinders.

a) Why was this? Is the v-6 better than the straight six in light truck applications?

b) Even today, this v-6 is the basic engine for bare bones/stripper new silverados/sierras; i don't think you can get a straight six in a new gm pickup.

1a) Probably (because it was cheaper) by basically being a passenger car engine. It certainly wasn't better.

2a) No, it was driven by development and tooling cost. As you say, the V6 was basically a V8 with the front two cylinders lopped off. As such, any tooling relative to the back of the engine could be shared with V8, offsetting some of the cost. Similarly, any learnings from the V8 relative to air flow, fuel control, etc. could be rolled over to the V6. It also was shorter, making it easier to package (and could share some of the mounting provisions, if not by part number at least in concept).

I should mention that a straight 6 is inherently balanced, in terms of both weight and firing frequency. The V6, on the other hand, is inherently imbalanced in both regards, causing shaking and vibration transfered into the vehicle (mine really "lights up" around 1500 rpm). As a result, there were a number of attempts to fix this through added hardware, like balance shafts or special engine mounts, which drove additional cost and eroded some of the previous savings.

K

[CaliDude76]

LOL..... Chevy with Lock-washers... Haven't heard that one.. i like it! I guess it's a matter of taste then, between the two makes.. I always thought GMC's looked a bit fancier.. but thats me... Junk-yard here has a 90 'Burb.. and the guy said he would sell me the front for the conversion on my truck for $225.. you all think thats a fair deal?? Thing is though.. its a GMC... wanted the Chevy front grille for that... but the GMC's not lookin too bad, I can pull the lettering off the grill i suppose.. Can anybody post pics of GMC front conversions????

[bluex]

Originally Posted by Keith Seymore

They went down the same assembly line, one right after another.

(In fact, sometimes the same truck was a Chevy on one side and a GMC on the other!).

K

Ya my dads first '78 was a chevy on the outside and had a GMC horn button and dash insert inside. He got it new.

Originally Posted by CaliDude76

LOL..... Chevy with Lock-washers... Haven't heard that one.. i like it! I guess it's a matter of taste then, between the two makes.. I always thought GMC's looked a bit fancier.. but thats me... Junk-yard here has a 90 'Burb.. and the guy said he would sell me the front for the conversion on my truck for $225.. you all think thats a fair deal?? Thing is though.. its a GMC... wanted the Chevy front grille for that... but the GMC's not lookin too bad, I can pull the lettering off the grill i suppose.. Can anybody post pics of GMC front conversions????

Sounds like a good deal to me, get the clip and sell/swap for a chevy grill. It will bolt in.

And since it was asked, personally I perfer GMC. I have always thought they were better looking...

[Keith Seymore]

Originally Posted by bluex

Ya my dads first '78 was a chevy on the outside and had a GMC horn button and dash insert inside. He got it new.

Some of you may have heard me tell the story of the "little white race truck" - it was actually built as a GMC.

We used to take it to Super Chevy events by swapping the grille and tailgate, but we left the exterior fender emblems, horn button and IP emblem as GMC just to see if anybody would notice!

[bharrison1]

i have been pulling parts off my grandpas old 86 GMC 1/2 ton longbed and have been surprised at the differences between it and my 87 Chevy 1/2 ton longbed his truck has the 1 inch rotors which is wierd because that truck has a V8 so you would think it would be more heavy duty than my truck which has a V6 his truck also had a one piece driveshaft while mine had the two piece til i swapped the one piece on it

[Scootin 81 C20]

Keith, here's another one for you. I don't know how factual it is, but someone told me that Chevy and GMC 3/4 tons differed in wheel size. Chevy ran a 16.5 while GMC ran 17.5? Can you clear this one up for me?

Also heard GMC spring packs had 1 extra leaf more than Chevy springs.

[OJOE]

GMC = german made cadillac

[69BBsuburban]

GMC's were generally a heavier duty truck, more of a work horse....at least back in the 30's to the 60's.....different options could be had than the Chevy's too....

[C-10 simplex]

Closest thing GMC ever had to a chevelle:

http://www.chevelles.com/sprint/

[f.monroe]

Originally Posted by dammitmitchell

GMC
Godly
Man
Charriot..
heheheh

Originally Posted by 1972SuperCheyenne

A GMC is basically a Chevrolet with lock washers!

Originally Posted by OJOE

GMC = german made cadillac

I was always under the impression that GMC = Got mechanic coming!

Just kidding. I dont think there are any real differences. Both trucks are square bodies so thats all right with me. I can only remember owning one 83 GMC shortbed. All others have been Chevys so i guess the main difference is the production numbers. GMC's are fewer in number around here.
Frank
Frank

[irishman999]

am i crazy or do all the gmc headlights stick out a little further on the square body trucks?