i had them milled to sqaure them and cut with a 3 angle valve job for 2.19/1.88 valve combo with new guides.i used manley raceflow valves with the necked down stems.i didnt do any port work because i want to evaluate before and after porting.IVE GOT THEM ON A .030 OVER 454 WITH SPEEDPRO 2399 FORGED PISTONS/RPM INTAKE/XE 268 CAM/PROFORM MODIFIED 750DP AND SO FAR I AM OK WITH THE COMBO. ONE THING THOUGH,ON BIG BLOCKS WITH A 1.7 ROCKER RATIO MAKES A CAM SEEM BIGGER THAN IT IS.I THOUGHT THAT I WOULD HAVE MORE THAN 15 INCHES OF VACUUM WITH CAM AND COMPRESSION.