The springs don't need to be that aggressive. I have RHS Heads done by Brian at IMM that are set up for a Solid Roller .634 Lift. Spring pressures are 145lbs Closed and 510 Open.
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Lots of factors play into it (weight of the valve train, RPM, ramp speed, etc), but as long as you can control the valve and not bounce the lifters you're good. Bouncing a roller lifter will destroy the axles in a hurry. 145 on the seat is like flat tappet territory...very interesting. I suppose it has a gentle closing ramp :dontknow:...idk, I'm not a professional engine builder.