the champs irons have a nice port and polish as is out of the box , compared to heads Im running with stock runners the champs are a huge improvement .
doubt youll improve on their current cnc program without tubing the pushrod holes for the 3 and 4 intake , its just not needed for 9s
bigger isnt always better, id rather know they were ported for even flow even if that meant they all should be smaller
if you go champion either get them with comp/manley PC seals or change them before you bolt them up , the teflon valve seals they use always seem to hang up on the valve