JL's how hot it depends on that your doing. and what charger and injectors your running. I could run like 1400* playing around or 2200* or more pulling all depends on what I was running for a setup
60lb springs are not needed. I run 4500rpm in my truck and 65lbs of boost and stock springs with titanium retainers and keeperes. 4 years and havent touched a piston to a valve yet. the afc spring is just the second spring from your stock governor springs.