I may have the answer for you, installing a SM420 trans without all the cost. I needed to replace my original 1942 235 engine it had a broken crank.I installed a 1962 235 engine with low miles got it running and installed. I also added a 1948-53 truck bell housing and SM420 trans behind it no more double clutching. I made a adapter plate to the bell housing to accept the clutch and brake peddle no need to have the piece with the three bolt holes from your old bell housing welded to the 1948-53 truck bell housing. Will post it as a Tech Tip at some point. If I say so myself it turned out great. Check out this posting in the Driveline Forum for more details. If anyone would like to add a SM420 trans to their truck call me for the details will be happy to help. 1-262-392-2989.

Marv.