sounds sorta like valve guide to valve seat alignment. i had some major issues with this after i had hardened valve seats put in. first off i had a valve get stuck from scoring the stem, this happend 4 times!! so i just had the machinist ream the guides to .345 fixed the stuck valve problem. something else i noticed with this, it sounds like i have lifter tick when hot not cold. no amount of adjusting can cure it. last time i had the heads off i could let gravity seat the valve(no spring). then pust it down and it would move sideways about .003 or so, and feels a little stuck when unseating them.