Quick question. Lets hypothetically say that I decide to stay with stock cast iron heads. How much would it affect performance if I didn't port them? Would simply installing biggers valves help with a nice combustion chamber polish? How well do the stock heads flow up to .500 lift? I'm just trying to look at all angles because right now I will be over budget. I still have to swap the spindles and disc brakes from the New Yorker to the Fury, and rebuild the trans.