Originally Posted by Dragula
If you have a hydraulic roller cam with relatively low spring rates, and then add a bunch of boost to it, do you have to increase valve spring pressure so the valves close?

Absolutely wrench
You don't want the manifold pressure to hold the intake valve open making the lifters float and you don't want the exhaust valve pushrods to bend when opening either so make both a lot better twocents

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)