Comp Cams recommendation evaluation

Then why did my Rat
Chev,pick up another 300 rpm,before valve float from the swap? It was .540" advertised lift,stock Chevy parts ?.....

Wow , you just don't see it do you.... The lifters made your cam look SMALLER to the valve spring, thus staving off valve float slightly before the spring totally lost control. Springs do not just suddenly go into float, they lose control of the valve train before you can feel it...:banghead: