When I was going through the cam change deal last year I spoke to Gaterman who makes the Hyd roller lifters for Howards. He told me some of the cam companies recommend too much spring pressure for the hydraulic lifter to operate. I can't remember the owners name but he was very helpful and eventually we came down to the solution for me was a solid flat tappet cam instead of a hyd, roller with my car being a manual transmission. Look up Gaterman lifters and talk to the owner there he is very helpful.

Gus