The Chevy bolt patterns for the bellhousing should be the same. I recently had a '56 Belair 3 speed behind by '63 230, then took the 230 out and put in a 70' 250 out of a Camaro and the '56 tranny bolted right up. Later I put a turbo 350 autobox from an '81 Monte Carlo into the truck. It too bolted right up to the '250......So a t350 should bolt right up to the '62 stovebolt engine...
Now the crossmembers are a different story. You have to take out the front and rear crossmembers and add a rear tranny mount on the back member. (That's as long as the '62 has the same frame as a '63)
e-mail me and I'll send you pics of how I did my crossmember.
