I was running a racer brown stx22 with a set of lunati springs P/N 73124 and it didn't work 136 seat and 355 open that cam has 276 @ .050 and 590 lift 1.5 rockers .630 with 1.6 It floated the intake valves and ruined them . I then switched to a lunati P/N 73121 140 seat @1.940 400 open. We shimed them to get 150 on the seat and 410 open. This worked to controll the valves but it started to wear the cam after a season. Same cam stx 22 had cam turned into a mushroom lifter cam Had schubeck composite mushroom lifters made. This worked great zero cam wear and was able to control the valves. Finding the right spring combo is an absoltue nightmare if your not going to run schubeck lifters or a roller cam. Flat lobes ruin engines, droped valves from floating valves ruin engines. I done both and it really hurts the old wallet. I don't know yet what this new combo is going to do we will find out soon.