Editing How to choose a SBC engine

I am considering a drive train to place into an '82 Chevy SWB 4x4. I want to set the truck up for some limited street driving, but will also want to off road with it frequently. The factory engine is a 305.

I have a 327 that was in a 3 ton grain truck. It was factory fitted with oversized valves, and always had awesome acceleration. I also have access to a 350 for rebuilding.

I am looking for some good advice on what power plant to build out, and pros / cons for each. I plan to rebuild the auto tranny currently in the truck. Suggestions on this are appreciated as well.