fd 56 sedan

I'm not sure if I'm in the right area of this site being a new member. I'm doing a modern engine swap into a 56 chevy sedan need help on what to keep or eliminate,(ie; afm. vvt, change cam and lifters) what would be the best gear ratio for the 6 speed auto? The engine and trans. are out of a low mileage 2011 GMC Sierra 1500 2 wheel drive p/u that used flex fuel. Any suggestion on who to use for ecu reprogramming and converting stock harness. I'm looking to have a nice all around car.