How'd I miss this one?

As mentioned the 235 would be a direct swap. Youll need to relocate the oil filter as it wont fit with the updraft manifold setup. If you want to use the old non synchro tranny you need nothing more then swap out the engine only and keep the bellhousing from the COE.

There is a difference in the bellhousing as the old one should have a 3 bolted pivot bar on the drivers side for the clutch fork. The sm420 wont fit the pattern on the old bellhousing.

You have a bit more work if you want to swap to the sm420. Its fairly easy, but time consuming. Check out most of my pictures on my photobucket account. I have a section in there where I kept the photos of my swap. There is roughly an 1 to 2" difference in length of the driveshafts also, meaning the sm420 is a longer transmission.

I believe Chevy used a crossmember instead of the mounts seen in my pictures of my GMC, so that may complicate matters to.

Hope that helps, Jeff

My 1953 Chevrolet
1947.1 Gallery
1972 C-10 1/2 Ton & 1972 C-30 1 Ton