Piston Choice on 318

the valves are too big,the engines will lose its intake velocity,unless your gonna turn it up to 7000 rpm or above.Thats what all the engine guys are telling me any ways.I am building my 318 with federal mogul flat tops,block not decked,302 casting heads,ported(by me)milled .30,mopar thin head gaskets,lunati voodoo cam,with 494 intake,513 exhaust lift,weiand stelth intake,750 holley vaccum secondary carb,904 with 2500 stall converter,and prob 391 gears.I dont know what its gonna do,but the parts are already in there way,and well see how it runs