383 needs more power

back to post # 6 you said max hp was at 4400 rpm that's way off with that cam in a 383 should be closer to 6000rpm so is your carb getting open all the way? someone could of installed the cam on the advance dots that are on some timing sets and didn't dial it in. are the secondary's opening up the spring could be too heavy or no vacuum to it ,with your engine you should be near 320 hp at the rear tires