How much was milled off the heads/block decks??
You did say you raised the compression. If you cut more than say .020 or .030 you would need to shim up the rocker shafts. Also, since these are non adjustable rocker arms, the valve tip heights are critical because everytime a valve job is done it raises that tip height. Also, if the cam has more lift someone better have checked the retainer to seal/guide clearance. If you do pull a valve cover, run a straight edge along the tops of the valve tips and see how in line they are. They shouldn't vary more than say a 32nd of an inch (.031").