The Stovebolt Site Forums The Shop Area Engine Shop GMC 248 swap for Chevy 235 in 1953 3/4?????

I have an old 1949 235 babbit engine my 43 chevy 3600, I want to swap out the 49 235 for a GMC 248 bearing full pressure engine. It look identical is it? any problems doing this? Please anyone done this or know of someone who has? Thanks.

Have you looked at the Tech Tip about replacing a 302 for a 216? The 302 block is the same length as a 248 and the 216 block is the same length as the 235.

The 248 is a couple inches longer than a 235.

Also, keep the 248's pressure plate and clutch assembly (most likely the bolt patterns for attachment to the crankshaft are different).

Thanks I have the bellhousing, clutch and pressure plate setup. Tranny all the same?

You'll probably need the Chevy bell housing for the mounts. It will fit the 248. And your tranny will fit. You'll need to move your radiator forward.

Back in the day a popular swap was a 270 gmc for a chev 6 you either had to move the rad forward or build a special water pump. Cant remember details on the pump.

one the surface they they look the same. gmc blocks are longer as stated. manifolds look the same but wont fit. the flywheels arent interchangeable. bellhousing is the same so you have to make up the two inches in the front plus a new mounting location. like tim said keep the clutch and flywheel assembly.

it can and has been done and i looked at doing it until i saw what i needed to do and just replaced it with a post 54-235 that i had rebuilt. with all the work involved to gain 13 cubes wouldnt be enough for me to do it.

This was and still is a common swap. My main concern with the GMC motor is that they are notorious for having cracked heads. My only GMC had a cracked head as were all the other heads I could find. Also get a Patrick's catalog, has lots of tips and how-to info on these motors.
www.patricksantiquecars.com
ph 520 836-1117