+1 what Mag10 said. Just get an "x-acto" knife and run it along the edges of the dome and valve pockets, its part of the "engine build" not part of the "piston manufacturing". Don't cut into it, just scrape it, IE: keep the blade perpendicular to the edge. If you have your ignition advanced, and the higher comp. ratio, pre-ignition (pinging) could be a problem, especially if you get some bad gas.

'04' Black America