I ran mine at 370lbs and .550" lift. It wouldn't make as much RPM as I had hoped. So I shimmied the lifters to near solid (ONLY .025" of plunger travel), and put 440lbs springs on it. Didn't change a damn thing with the RPM...

That to me was a true test, meaning at 370lbs it wasn't floating a valve or collapsing the lifter.