058 is right on. Port matching the intake really doesn't do that much for flow, but it does do some. As long as you're careful you shouldn't have any prob's. Blend the bowls on both and REALLY open up the exhaust. It will definitely help! If you do put big valves in it you NEED to unshroud the valves in the combustion chamber. You take a head gasket and trace it's outline around the chambers. Then you blend(read:grind) the chamber almost all they way to the edge of the gasket(leave about .010 till the gasket). Only do this where the outside of the valve is. If you don't unshroud the valves then you won't get hardly any increase in flow.