[Brian]

Assemble your short block, then machine the heads to achieve the desired .040" odd thou quench. Getting that clearance from top of piston at TDC to head to within .040-.050" is paramount for optimum performance. This is pretty well the last step in building your mighty power plant, you need the short block assembled, then modify the heads to suit. I hear you say you don't want to mill the heads; you may well have to! Or, as you say, machine over the valves to achieve clearance, again, you may well need to. Putting all that lightened stuff into the engine is all well and good, but a waste of time if you don't prep the heads...