The Stovebolt Site Forums The Parking Lot Big Bolts 1967 GMC Bus V6 engine identification

So I've been gifted with a 1967 GMC chassis school bus. It's already been RV converted, and it's a professional job too.

My first task is to get it down off the mountain, and to do that I'm going to have to get some radiator hoses and other things. I know it has the big V6, but that's all I know. I've included pics of the engine ID code found on the block, and of the VIN.

The rig has air brakes and a 23,000GVW rating, so it seems like the next size up from my 1965 C60, which has hydraulic brakes and a 19,600 GVW rating.

Also on the plus side: NO WIDOWMAKER WHEELS!!

So my first of what are sure to be many questions is, what model and displacement of V6 am I dealing with here, and how may I go about finding part numbers for things like belts, hoses, etc?

It is a 351 Cu in "C" revision, V6. Good torque, low RPM. Built to pull weight. Very reliable. Long lasting. Not worth much.

If all you want are belts and hoses. They can be measured and purchased generically. More serious parts: Check Rockauto.

VIN could be S= School Bus, M= V6 gas, xxxxxxxxxxxxxx?

Thank you!

It's a good thing the engine is built to pull weight, because this rig has plenty of it!

Get it down off a mountain? Once you get it running, make sure you check the air system and brakes -- go over the lines, pressure check, grease and adjust the mechanism, etc. If you aren't familiar with how t do all that, get somebody to show you.

You are fortunate the thing has air brakes. They are a lot easier to fix than hydraulic. I have about 20 old trucks. The ones with air stop, the ones with hydraulic don't stop. It has been almost 60 years ago I bought my first truck with air brakes. I still run a fleet of a dozen semis.

Agreed. I'm familiar with replacing lines, wheel cylinders, and bleeding hydraulics. Not as familiar with air brakes, but can learn. I'm glad this one is air brakes, and the compressor looks fresh enough to back up the previous owner's claims of it being recently (before it was parked) overhauled. The oil in it looks super clean, too.

Since there is no combustion in the compressor, the oil does not turn black but it is possible that oil goes into the system. So check the oil level in your compressor periodically to make sure it has oil. A 1967 model should have Synflex (nylon) lines already. They last forever unless they are exposed to sunlight. You will probably have 3 or 4 rubber lines that should be replaced. 3/8" pipe fittings became standard in 1975 so yours are probably still 1/4" but they are still available. You will probably want to change brake chamber, which are still available. If you need help in finding vendors, I can make suggestions.

A couple buddies and I owned a '66 GMC 48 passenger school bus back in the 80's. Had a lot of fun with that ride. Doesn't require a canoe rack, just open that back door and slide it in. Eventually sold it to my brother and he used it to transport his rock band. It had a V6 as well. After they blew that up they went ahead and installed a 350 Chevy.

John