Anyways back to the build.....
I have decided to add the oversized valve, spring, and hardware package from supertech and crossover auto through PG. I'm going with the single spring for a little extra closing power and because im not pushing redline too much. There is no reason why my head shouldnt breathe well at high rpms now! The limiting facors will now probably be the intake and exhaust like LW said. PG has agreed to port and polish the head and size for the bigger valves all in one step!
Awesome stuff. High RPM breathability will also be helped by the lift on the twiggy cams, which is considerably more than the stock or ZE cams.
you going to get any work done on the combustion chambers ? weld and reshape perhaps? or something a little less extreme like volume matching and ceramic coating?