The Stovebolt Site Forums The Shop Area Engine Shop help with a 1968 Chevrolet/ GMC powered by what is believed to be the 478M

I have bought and are currently restoring a 1968 Howe fire engine. it appears to be a Chevrolet cab with a GMC power train. the owner manuals that came with the truck have the 478M circled in it identifying it as the engine that is in it. But I have been unable to locate the engine code on the block. the engine runs great and only has 24k miles registered on the odometer. I m new to the site and if I can figure out how to post pictures I will.

Welcome to the site. It appears your question is "Where do I find the engine casting number?" I'm moving your post to the Engine forum.

Pictures must be hosted elsewhere and linked to here.

GMC trucks have the SN starting with the displacement, I e 478xxxx. Look on block near intake manifold, or rear near head attach.

Ed

thanks for the info. I will look in those areas. also I've always been a Ford guy so I'm not to familiar with the GM history. but this truck was just to good of a deal to pass up, also i always wanted to restore a firetruck. the cab is a Spartan 80 tilt cab and but the center of the steering wheel has a GMC badge and there is GMC emblems on the engine and transmission. i was wondering why there would be 2 different makes combined in 1 truck.

the big block v6s have the engine size stamped on the block just ahead of the cylinder head on the passenger side, behind the fuel pump.