The Stovebolt Site Forums The Parking Lot Big Bolts 248 to 235 or 250 engine swap

The 248 in my 53 GMC 353-24 appears to need a total rebuild. So at this time I am considering other options. I know that I can use a 235 with my present bellhousing which would only leave me with the front mount to solve. But I am also wondering about using the later 250 engine which would require a different bellhousing possibly one like this http://cgi.ebay.com/ebaymotors/Bell...Z013QQcategoryZ34208QQrdZ1QQcmdZViewItem ? Would this fit the existing rear mounts and if so what would be the easiest solution to the front (side mounts)situation? Has anyone done either of the above engine swaps and if so are there problems to look out for? :confused: Thanks

You can also use a Chevy 261, which fits the same as the 235, or the GMC 270/302 motors, which do not require a front mount change and which drop right in place of the 248.

It does not simply fit. Note the angled mounts on that bellhousing. Your '53 has a flat mount. You can make an adapter or swap to a '54 crossmember.

As for the front mount issue, most of the published information I've seen is for going the other way. The GMC motor is longer, so you would need to find a way to support a slightly shorter motor. I know its been done, but I've note actually seen one to tell how it was done.

Actually I have a GMC and a Chevy, without front sheet metal or engine and transmission, sitting in the yard. I could take some pictures to show the difference. Would you like to see those?

Oldsub, yes I would like see any pics availble. Thanks

If it were me, I'd stay with the GMC 248, 270, or 302.

Well I wandered out back and took some pictures. This time of year my back yard is pretty over grown, so I just kicked down some grass and shot away.

For a couple of reasons I've decided to create a web page with my pictures and explanation and just post a link. First, a page is easier for me to find again (threads age), and I've had this discussion before, and second, this way no one has to load my big pictures if they don't want to.

You can find the pictures here. OldSub\'s Crossmember Page

Yeah Spanky I agree. Too much trouble to swap to a Chevy. And the Jimmy is a better motor in general.

I love my 270.

But rather than just say it I thought it might be more persuasive to show some of the issues that have to be dealt with going either way.

steve is the gmc sway for sale? email me at joromero4@msn.com

OldSub, Thanks for the pics they explain alot. I got to do some more thinking and planning on this old truck. I hope to get the head off of the 248 today.