Years ago, I had a machines shop do a 3 angle valve job, install new bronze guides in a set of factory 2.02 340 "J" heads. I pulled these heads for a set of 596 smoggers with 1.88's that was home ported and just lapped the factory valves. Dropped 3 tenths. Just how things work out sometimes.... :) I guess home porting might pay a little now and then. :D