Hi Everybody
I have the oppourtunity to buy a rebuilt 350 , 4bbl. carb (with 31k miles) out of a 3/4 ton chevy Van 30 (Commercial) to replace the old 350 (out of a '77 Caprice) in my 64 Impala. My mechanic since the engine is out of town cannot look at the van's engine, wonders if the vans motor mounts would match up with the Impala. Or if not would it be a lot of trouble to make it safely fit?
Also I believe the dipsticks could be easily worked out and my ramsheads exhaust manifolds could be fitted on the van's engine. (the van has 2 exhaust pipes, the impala 1.) Any advice on any of those items or any other possible issues? I don't want to get stuck buying labor and an engine that does not fit!
Thanks much
Rick G.

The only time you'd have problems with mounts is with early small blocks, I believe up to 1957, that did not have side mount provisions. Every small block since 1957, Gen I and II (LT1) have the same mount location, so you will be good to go.

The only potential exception to that is some truck blocks, which seem to have slightly taller mounting bolt bosses and therefore a bit more "spread" in the locations of the engine mount through bolts. I'm not certain if this is by design, or if it was a machining flaw which happened most frequently on four-bolt blocks - those are the only ones I've encountered that way. Usually they can be "adjusted" enough to make them fit, but that usually is discovered just as the engine is being lowered into the crossmember. It's no wonder the front mounting plates are still popular among some racers.