2 barrel Hemi!!!!!!

I know zero about Harley's, are those factory pistons or aftermarket high compression pistons?
Well, being an actual Hemi head engine, with the 180° hemispherical combustion chamber, you can get away with pop-ups like that, without a bunch of unnecessary modifications. However those are Forged Custom built racing Pistons from Manley. Very few of those were manned, in fact, they are not even available these days, haven't been since the 70's Brother!