When you get up around 450 H.P. you might want to think about a forged crank. An Eagle 4130 should do it .5140 steel rod's ,S.R.P. forged piston's. Use a good oil pump , Melling's or Moroso .Stay away from exotic stuff, like gear drive's, roller rocker's and racing ignition's. Stick with the basic's , screw in stud's with guide plate's on the head's. 2.02 intake valve's 1.6 exhaust Manley's. Comp Cam's X-Treme Energy cam's are good 274/286 adv. dur. .487/.490" lift should run in the 1800-6000 R.P.M. range. This should idle lopey and give plenty of power around 400+ H.P. Do you have any idea's for induction carb or fuel injection? An Edelbrock R.P.M. Air Gap manifold with a Holley 600 vacuum secondary Carb should run to 6,000 R.P.M.'s I like jet's in both side's of the carb for adjustabilty. Good luck on the engine.