I have a chevy 400 that apon decelleration from above
5000 rpm it back fire and it sounds like a gun(BANG)!!~
I have messed wit my timing and found its sweet spot.
I have 750 demon and found its sweet spot.
The only other thing that i can think of is maybe a tite
valve. And since its out the exhaust i am think maybe a tite exhaust valve. But i also have a header pipe at the collector
flange a pipe is broken alll the way around i have heard that
exhaust leaks can create backfires. dont know if this is true
or not Any help is greaty appreciated




Bryon