The Stovebolt Site Forums The Shop Area Engine Shop what is best 248 or 302??

I have 2 1953 GMC pickups,I will be making one from both.These are Canadian trucks which are basically chev trucks as they have the 216 engine.My question is which engine is best as I have a GMC 248 and a GMC 302.Iis this a difficult swap? also will the 248 clutch housing fit the 302?
thanks for any info

The 302 is the holy grail of GMC sixes. Finding blocks can be a problem. I don't know about the bell housing. The 248 is a good engine, in it's own right. If I were wanting to put a GMC six in a truck, I would get a 270. Blocks are a lot easier to find than the 302.

Hy masseyharris, bellhousings interchange within the G.M.C. line 228 236,248,256,270,302, and across to the Chevy line 216,235,261. The G.M.C. engine is longer than the Chevy, so adaption or crossmember replacement will be necessary, also the rad. will have to be relocated, hope that helps.

I've looked into a 302 a little bit. They aren't that hard to find, but they are expensive to rebuild, especially to warm them up. My current pipe dream is to wait a few years till my son gets older and hot rod a '39 or '40 pickup w/ a 302, 5spd and a F@#d 9" rear. At 3 1/2 he's pretty much into cars and trucks, especially trucks.

Best is send me the 302 and keep those Canadian trucks completely original with their Chevy motors.

Along this same line; how hard would it be to bore out a 248 to make it a 270, and are the cranks the same?

The 248 has a shorter stroke... I think 3 13/16 of an inch. The 270 and 302 had a 4 inch stroke. It was popular to put the 248 short stroke crank in the 302s to reduce friction and rev higher. Some torque would be lost, and some upper range performance would be gained.

Putting a 270 crank in a 248 would basically give you a little bit more stroke and increase torque. I'm not sure how many cubic inches you would pick up.

Hey bigmacdaddy... That is exactly the project I am working on now... 1940 gmc, 302 with a nv4500 5speed and f@rd 9 inch rear with 4.11 posi. I hope it comes together in person as well as it sounds on paper!

That's awesome and weird. 1st the name and now this. You would think I was copying you. Great minds must think alike. How about some pics?

I've got a 302 also, just picked it up last month. It's going into my '50 Chevy with a 4 speed saginaw and 3.07 rearend. I'll be fuel injecting it after I get it running and set up. It has a 2bbl Holley and a governor on it right now. It runs but smokes a bit.