So I have a fresh 545 with AFR bullit heads, hyd flat tappet cam, AFR intake. At about 4300 rpm I'm getting a popping in the exhaust and the motor falls off. I currently have a Holley 950 with 84's on all 4 corners. My fuel pump is 145 gal per hour and 6 lbs steady with a return. I am using a Pertronix Flamethrower Dist and coil. I have tried 3 different ignition systems so I think I can rule that out. The cam was broken in per the instructions and I have checked for a flat cam lobe. As far as I can tell the cam is good. I checked with Comp Cams on my cam/spring compatibility and all is good. Any help would be great.