Ive got a ****ed up situation. Engine still on stand. Stock block from a 95 GT HO, that recieved an F303 cam, stock heads with 3 angle valve job, 1.6 roller rockers, stock lifters, stock pushrods. Theres alot of other **** but this is what matters. So I bolt it all together and install rockers only to find a CRAZY amount of difference in lash between rockers on different cylinders. When I say crazy some have none while others have .066" and not even touching valve stem. YEah crazy. So then I primmed the oil system thinking the lack of oil pressure was the difference, NOPE helped some but not much. Ive been picking my freaking brain on this one. I know its a bigger cam with smaller base circle on the lobes, but why only some intake or exhaust valves why not all. So I pull everything back down, and put a straight edge on the tops of the valve stems and can see daylight huge differences in install height. I figured well thats the problem, so I pull the heads back off and give them back to the machine shop and say FIX THEM