i have a true 69 440 six pac motor rebuilt using kb quench dome pistons for a true 9.7.1comp mp 484 cam everything else bone stock orig.dynoed the motor through the manifolds with air cleaner on just as if it where in the car and made 438hp/476ftlbs no tunning etc just a stock rebuilt.i think with porting better cam and playing with carbs and 10.1 would get you 500.