Thanks, Pat - food for thought! I had forgotten that the timing of valve opening/closing events can affect clearance with the piston, not just valve lift itself. I have forged TRW L2399F pistons with .095" (13.8cc) dome on Manley H-beam rods.
A couple of questions - what do you mean by hippo roller?? Do you mean high performance? Would you advise a steel billet cam and the best roller lifters I can find? I've heard about a company that makes roller lifters without needle roller bearings, just plain bearings like on a crankshaft.