1957 gmc 9300

Question for the inliner experts. I have a '57 9300 GMC (Canadian) ,having trouble identifying the engine casting #....C 232869.....head casting # 3836848 ....my thinking is it's a 261 but not sure . Have checked several sources with no luck ,any help would be appreciated !

 

270 or 302. I think you may be missing a # on the engine casting

 

That's definitely a Chevrolet head casting, very common.

 

Had that idea too......rechecked block and vin tag match ......# C232869....my understanding is the GMCs made in oakville have chevy engines in them ,likely has something to do with this different casting number .

 

If it's Canadian built GMC it will be a 261.....

 

Not to hijack, but as long as the subject has come up, will a 270 GMC flywheel fit a GMC 302, and if so, does anyone know where I can get one?

 

It depends some have 4 bolts and some have six. Most 302 have the six bolt flywheel. OldWolf

 

Thanks Oldwolf. My 302 has 6, but I was told many moons ago that a 270 would bolt right on. Even if the inside diameter of the crankhole will fit over the large 302 crank, I could tap the necessarry holes. But I've tried several GMC and Chevy flywheels and they're all too small. Having a hell of a time finding the 270 flywheel.

 

I don't think that it's a 261. I did some research before on them and here is one of the pages that I looked at before. The casting numbers don't match. http://www.oldchevytrucks.com/Tips/261_six.htm
Hope this helps.