The Stovebolt Site Forums The Parking Lot Big Bolts Olds or Pontiac eng in GMC? know of such a thing

Some years ago I had a 1955 GMC Bobtail dump truck with a Pontiac V8 Eng. Today I heard from a friend that he pull an Olds 394 V8 from a 1956 GMC cement truck.

Just wondering if anyone else has run across either?

I think GMC used a Pontiac V8 back in those days, and Chevrolet used Buick engines. This was before they had V8's of their own. I have never heard of an Olds in any one of them from the factory. This might have been something that someone did themselves.
Jim

It seems that according to Wikipedia from 1954 to 1956 the was an Oldsmobile 370 CID Eng. that was strictly used in GMC only. And in 1957 through 1960 an Olds 371 CID was used by GMC.

So far nothing about Pontiac Eng s in GMCs.

This came up today because someone has given me the Bell housing, Flywheel, two (yeah 2) dis-clutch and pressure plates. This out of a GMC Cement truck. It has the same style recessed flywheel as my 1953 GMC FC454-30.

Now all I need is an Olds 371 CID or 370 CID Eng with J2 setup for my 1948 GMC FC253 1Ton dually flatbed, with SM420 and Watson series 30 Auxiliary 3 speed U/D/O.

And I can fly....weeeeee

And we will be flying.

Mike Boteler has a '56 Chevy L.C.F. tractor,with a 322 Buick/auto set-up. I THINK that Chevrolet used the Buick power plants,whereas the G.M.C.'s were powered by Pontiacs,unless special ordered. On youtube,"Redneck Restorations,Jefrf Bradshaw has 2 '55,'56 T.F. G.m.C. 1-tons,as well as a T.F. G.M.C. short box,all "Poncho" powered.Several T.F. G.M.C. trucks the "Gallery", are Pontiac-powered,as well.I THINK I saw a tandem-axle T.F.,('59??) Chevy,on "Craigslist,a while back,powered by an OLDS.Please correct me,if I'm mistaken.Thanks.

Chevrolet did use Buick in their heavy trucks for a few years until they started putting their 348 in the heavy trucks. Chevrolet never used Oldsmobile or Pontiac power.

my 59 gmc has a ponco motor in it from the factory. 55-59 trucks had a version of the pontiac engines. my 336 is based on the 389. It has the same stroke but smaller pistons.
From the web
"Prior to developing their own engines, GMC used the Chevrolet Straight-6 engine and Pontiac V8 engine. They used the Pontiac 287-cubic-inch (4.7 L) motor for 1955 and 316-cubic-inch (5.2 L) motor in 1956, but advertised the engines as the "GMC 288" and "GMC 316". They used Pontiac's 347-cubic-inch (5.7 L) in 1957. For 1958 and 1959, GMC reduced the bore of Pontiac's 370-cubic-inch (6.1 L) to 3.875 in (98.4 mm), resulting in a displacement of 336-cubic-inch (5.5 L). In Canada, however, GMC used the Chevrolet Small-Block engine rather than the Pontiac."

The only GMC trucks that I know of that used Chevrolet inline 6's, are the Canada built light duty trucks.

My 59 GMC LCF has the inline 270 Pontiac engine, or at least the tag on the glove box lid says Pontiac, Mi.

270 is a GMC truck engine.

My '38 GMC truck had an Olds 230 flathead in it, GMC also used Pontiac flathead sixes. I the '50's, GMC used Buick, Pontiac, Olds engines in their trucks.

Hy Guys, GMC used Pontiac V8s in up to the 500 series or GMC inline sixes, the larger series used Oldsmobile V8s or GMC inline sixes that is the U.S. produced trucks built from 55"B" or 2nd series to 59. The Canadian produced GMC trucks are a different and much more complicated story,hope that clarifies.

"Prior to developing their own engines, GMC used the Chevrolet Straight-6 engine and Pontiac V8 engine.

Partially true. GMC did use Pontiac OHV V-8's in th emid 50's as has been stated but they never used Chevrolet inline 6's in the 40's-50's. There are many differences in the two brands as most all here are aware.

My 55 GMC has a 287 Pontiac V8.....although GMC called it a 288. Perhaps they thought people would think it was a different engine.

Tad

Hey,

Anyone out there have an 1957 or 58 Olds 370, 371 or a 59-60 Olds 394 CID, just laying around they don't need? ;-)

Is this for a G.M.C.:)? Replacement engine?? Wish I knew of one. Try Jeff Bradshaw,in Selma Or. He specializes in T.F. trucks,mostly 1/2-1-tons. He does part out big trucks,as well. www.elderlyiron.com/"Redneck Restorations:This Old Truck". I bought parts from him before,and the prices and shipping are reasonable. Hope this helps. Wouldn't hurt to post an ad in "Parts Wanted". Reach a bigger audience!