468 BBC backfire problems

[infotraker]

BBC 468, dual 650 Hollys (Proform body upgrades) on tunnel ram. Last time out (after Proform body upgrade) exhaust backfire at full throttle. When coming back to idle occassional carb backfire and engine quits. Running #31 quirters (came installed in Proform bodies), 73 primary and 80 secondary jets, did not change jet size when upgrading bodies. I want to get back to fixing the problems next week. Any ideas what to look for and change ?

[Moneypitt]

BBC 468, dual 650 Hollys (Proform body upgrades) on tunnel ram. Last time out (after Proform body upgrade) exhaust backfire at full throttle. When coming back to idle occassional carb backfire and engine quits. Running #31 quirters (came installed in Proform bodies), 73 primary and 80 secondary jets, did not change jet size when upgrading bodies. I want to get back to fixing the problems next week. Any ideas what to look for and change ?
Popping in the exhaust at full throttle is a good sign you have too much fuel in the cylinders. The spark can't burn it all in the time allowed. The excess unburned fuel enters the hot headers and fires in the pipe. Lean the motor down a bit, it is too fat.........You have alot of fuel, and not enough air......MP