already got the auto trans.(350 TH) rebuilt and ready to go for 100.00, I'm leaning towards a 350 cid engine , plentiful and dependable , unless someone gives me a good enough reason not to ! do I need a new wiring harness , like a painless , or can it be done with the existing wiring ? also would you suggest a 2 or 4 barel carb ?wouldn't the motor mounts and trans. cross member be enough ? I'm putting a lokar 23" auto shifter in .