scab vender putting a 350 cu in engine in is easy as any any other engine. Just because it has a X- frame it is a little tite on the tranny area. I have a 350 cu. with a 400 tranny and it fits which is just a shade bigger. The only thing is you may have to modify a factory after market one or make your tranny mount which is what I did. You will have Approxmately 5/8" 3/4" if you use the Rams Horm 2 1/2" center dump manifolds. You will also have about 1/2" clearance on the GM. Rebuiltable Fuel Pump.
The Standard Rams Horn and Fuel Pump will give you a little more room to work with without notching the frame areas. One more thing BESURE YOU USE THE RIGHT MOTOR MOUNTS! Good Luck
62Blue
Don

62Blue
62Chevy in progress
You've never been lost until you've been lost at Mach3" Paul F Crichmore (Test Pilot)