Ok started running the solid lift head. Just changed the cam in it and put mouse traps. Ran it 2 laps in hotlaps and about 6 of the lifters backed all the way off. ... Ok so I thought I may have not snugged them good. So we set them again and I made SURE they were very tight. And 3 laps later same thing. I never had the problem with this head until now with a diferent cam and mousetraps.