Thanks to this forum, I now have a pretty good idea of what I've got in terms of a drivetrain, now I need some help deciding whether to rebuild it, or replace it. The car is a '63 Chevy II 2-door hardtop. A previous owner replaced the original 6 with a 30 over 350 small block, but kept the Powerglide. The engine is no great shakes, being a 72 or 73 truck engine with 76cc heads, Torker 2 intake, and Carter AFB 750 carb, and stock exhaust manifolds. My goals are pretty modest, to make 320-350hp, and to run cool in city traffic.

Of course, money is tight. Should I tear it down and take it to a machine shop, then re-assemble it with a kit, or will I be better off with the low-end (290hp) GM crate motor?

With my existing block and heads, will I be able to reach my 320hp goal with headers, and a different cam and intake?

Should I keep the powerglide, or swap in a th350? All input is appreciated, cause this is all new to me. Thanks!