What cam brand is being used?

Yup - I don't use MP stuff anymore due to production issues I started seeing (read that as they were ground like **** and I was having to move them all over to get where they should have been in terms of installed center line). Otherwise I've used pretty much all but Oregon with favorites being Comp, Crane, and Engle. I wouldn't use a hydraulic roller. Either step up and do a solid roller with lifter bushings, or stay with a flat tappet would be my advise.