Something else to add to the pondering, I replaced my 269/275@ 50 flat tappet with a 269/275@50 roller. Just looking at the cam sure looks like more duration to me in the roller, round nose vs a pointed nose. Something else, picking the exhaust opening for a 511 wedge should be much different for a 572 Hemi i would think, just to get a handle on the escaping input charge. Mine is not much different from my 511 wedge, 3*later on the Hemi cam.