I currently have a chaparral 2350sx and a new 454 with +.040 overs with a 9.5 to 1 compression, cam is a .500 lift on intake .510 on exhaust running a 750 quadrajet orginal carb.I know that it is running out of fuel on top end (4900/5300). As of now I can only get 4900rpm out of it. should I change needles in the carb or switch to a marine Holley.Oh yea the motor was a 454mag before I got a hold of it.Please help with this problem.forgot to say fuel presure is fine 5 and a half to 6 psi.