What is "GMC" ??

[Tin Knocker]

Originally Posted by jcanavera

At one point in time I heard that GMC's were "work vehicles" and physically differed in some components and were considered more of a heavy duty vehicle vs. their Chevy brothers.

Very true. They were also cheaper to repair, at least into the mid to late 70's. Chevrolet sold 'assemblies' while the GM Truck dealers would sell individual components. One example: the front rotor on Chevy trucks was one piece with the hub, GM trucks were individual components. You could buy either part from the GM dealer and once assembled they would interchange with a Chevy rotor. This was from the heritage of heavy duty trucks. GMC V-6 and V-8 gas engines had the spark plugs on the top of the heads, mechanical fuel pumps mounted where they could be accessed from above, etc. Down time often meant no income so easy maintenance was important.

The engine below is a 478 cu. in. V-6.

[Frank S]

Hi All Who Contributed To Above--This thread really developed into an interesting history of GMC. I really enjoyed it having spent 39-years with GM, and now retired for 14.--Frank S

[scottanlily]

Hello Tin knocker,

The olds and pontiac engine usage was in the early 1900s upwards of 1920
cannot say for how long ,but the GMC info on that is clearly documented.
the v8 in the 56 does sound odd ,but It is original.GMC did not have their own v8 ,hence the big v6 usually a 302 displacement.Another unusual GMC
v6 piece of trivia are the v6 plaid ,yes plaid as in that checkered scotish
look, on the valve covers of some GMC v6 trucks .Frank S may have seen these . I hear a marketing idea someone came up with .I have seen those as well .THe covers look like the chrome ones on your 478 huge v6 ,but were
painted plaid .The 261 GMC inline came in the cabover engine truck 2 ton.
My 1950 coe came with a high pressure oiling 235 ,the GMC being a much
heavier duty engine.

Scott

[john hd]

scott

do you know anything about gmc straight eights?

i saw a tow truck once that had one, the owner claimed it was the largest diplacement gas engine ever used in a gm truck.

btw, we used it to help tow a 50 ton crane to the top of rib mountain in wausaw wis, to erect a radio tower! it had no problem towing the crane!

john

[65glbtrotter]

Originally Posted by jcanavera

I'm sure its probably the same on most of the truck line.

Jack

After owning a '98 GMC Sierra that was ran into while parked in front of my house, and getting an '04 Chevy Silverado as a rental while my truck was in the shop I will only buy GMC trucks they drive and handle better. That is why my truck now is an '05 GMC Sierra after test drives on both the Sierra and a Silverado.

[Mike Lewis]

When I worked for a GMC dealer and was asked what was the difference between a Chev. and GMC we always said nothing. They were the same truck, built on the same assembly line. When they came to the inspection point those that pasted got GMC emblems ,Chev emblems went on all others. Later I worked at a Chev. dealer and ,you guessed it, the story changed.
Pieman

[Frank S]

Hi 65glbtrotter--Although GMC and Chevy pickups were different in the past, currently they are the same mechanicly. I would think the driving difference you experienced might have been the result of having a 4.10 rear in the GMC, and a 3.73 rear in the Chevy test drivers. I stick with Chevy, as I travel a lot, and Chevy has more dealerships available around the country for service. Just my 2-cents worth. Enjoy your GMC Sierra, it's a winner.--Frank S

[Frank S]

Hi--Forgot to add that GMC will again position the truck line to an upscale position, above Chevy. Larger engines, more options, higher trim levels.--Frank S

[60pacerhobo]

AMC. Aint my car. Have seen at least 2 1956 GMC pickups w/pontiac engines.Makes sense too cuz pontiacs & GMC were often the same dealership.Poor Old Numbskull Thinks Its A Cadillac.

[Condoluminum]

Jack said it well... GMC and Chevy trucks, Suburbans, etc come down the same line built by the same people using the same parts bins.. Different grills, logo emblems and manuals are the differences today..

If one handles differently, it is due to different options, suspensions and tires, not any design or "quality" differences between the two.. Even GM commercials always have to excuse any other GM truck from comparisons, since they're identical..

I've been into two GMC dealers asking them to explain price premium (GMC's do sell for higher prices..) and they are unable to answer other than "more upscale.." which I don't understand...

What I do understand is GMC dealer won't honor a Chevy Truck warranty, and vice versa, so if you ever travel away from your home dealer, and have a warranty problem, you're twice as likely to get it fixed in a Chevy than in a GMC, since that is ratio of dealers... I guess some people just like the looks of the blacked out grille... YMMV...

John McG

[overlander63]

Originally Posted by 60pacer

Poor Old Numbskull Thinks Its A Cadillac.

Chevrolet= Completely Hopeless Every Vehicle Relies On Leftover Engine Technology.

[Anon]

Originally Posted by AZstreamin

how about General Motor Coffin.......one of the big three will be owned by someone else before the end of next year

Now that, I would take a bet on.
Doubtful that it will be "owned". Definite consideration can be given the fact that another car company could become a "major stakeholder" though.

[scottanlily]

Hello john hd ,
Nope haven't seen one ,interesting for sure .The pontiac and buick straight 8
engines are the only ones I have seen .as I am reading the first 100 years of GMC ,it states that in 1938 they used a pontiac 222.7 cid 6 and into 39 an
oldsmobile 229.7 cid 6. It shows that the pontiac plant was building trucks.
Now in 1955 a 287.2 cid pontiac v-8 was an extra cost option ,the 316.6
pontiac v-8 was installed ,same as the 56 pontiac car engine.It appears
this continued until 58 59 only ,then the new v-6 302 came along as the
new engine. Now as to the chevy / GMC difference we all pretty much know
that today there is no difference ,pattersontoo is right about chevy and their
future holdings ,and ownership of the company ,they have been really lucky
with the hummer /GM partnership and the light truck line .who knows though
maybe that camaro ,retro vette looking car might help them ,but I suspect
they will want 40 grand for it.

Scott

[john hd]

scott,

i talked to one of my old coworkers he reminded me the tow truck had a V12 not a straight eight as i thought.

did a little research i found this, check it out! 702 C.I.D.!!!!!! basicly two V6's glued together!

[Mike Lewis]

John--I know I'm telling my age but here goes anyway. In the spring of 1959 I was a 18 year old cocky kid right out of automotive school, Nashville Auto Diesel College, and had hired on at a little country Chev. dealer in Morrow Ohio. They were so lucky to get me as at that age I knew "EVERYTHING"!!!! Anyway being the lowest on the seniority I was selected to got to the GM training center to be trained on the newest GM idea, the Corvair. A whole "nother story". Anyway when at school they had several GMC trucks with these engines in them. I thought they were proto types at the time but found out they were available in production. Am not sure how many but some. They were not exactly gluded together as it was in fact one cylinder block that had the appearance of 2 cast together. They did have 4 cylinderheads 2 intakes ,and if my memory serves me correct 2 distributers.
It was my understanding they had one piece cam and crankshafts. It was but one of the many trial and error items GM as well as Ford and Chrysler had in those days. As I always say,"What makes the good old days the good old days, is a poor memory".---Pieman

[59toaster]

Originally Posted by Frank S

I stick with Chevy, as I travel a lot, and Chevy has more dealerships available around the country for service. Just my 2-cents worth. Enjoy your GMC Sierra, it's a winner.--Frank S

I use to take my company GMC to a Chevy dealer all the time for waranty work. Never had a problem. I took it to several different Chevy dealers infact.
After it was out of warranty only the local Chevy dealer worked on it, the GMC dealer wouldn't take the Fleet card.

[scottanlily]

Hey john hd,

Great factory literature there ,yes I did read about the v12 offered ,yes the twin six, the book says about 1000 of those babies were installed in the bigger trucks ,bet it weighs a bundle ! Did you guys know the detriot diesel
with the 4-71 6-71 and 8-71 blowers were the ones used in the early days
on hotrods ,mainly the 6-71 ,the most popular ,the name Dyers comes to mind as well ,probably spelled that wrong.As in a dyers 6-71 blower.That
twin six does look like to v6 s molded together .There was a hotrod guy
back in the 80s that had made a v16 as in two 350 chevys molded as one.
Falconer was the name .had some photos in either Car Craft or Hot Rod
magazine .Interesting .

Scott

[Frank S]

Hi overlander63--I got a good laugh out of your definition of CHEVROLET--Completely Hopeless Every Vehicle Relies On Leftover Engine Technology--and you are right. There is much better engine technology available in the market place today, however there is a lot to say for "tried and true". The basic pushrod engine has good HP and torque and is: less expensive to manufacture, parts are available everywhere, mechanics are familiar with them, gutsy, dependable, long life, easy to rebuild, and reasonable cost of repair and replacement when long service life expended. I've had a lot of Chevy small blocks and love 'em. Frank S

[2airishuman]

Originally Posted by AZstreamin

one of the big three will be owned by someone else before the end of next year

didn't this already happen?

how about 2 outa 3?

cheers
2air'

[AZstreamin]

Originally Posted by 2airishuman

didn't this already happen?

how about 2 outa 3?

cheers
2air'

Not yet, I was referring to GM. The Billionaire investor Kirk Kerkorian has a significant share of GM but he has been in talks with Nissan and Renault to negotiate another 10 percent this would put him in a strong controlling position and likely boot CEO Rick Wagoner. I'm assuming you’re referencing Daimler as the second which already happened awhile ago.....As much as I love cars there is good reason why I don't recruit for the automotive industry their supplier have a love-HATE relationship. no bueno.