I have a 383 in a '71 Duster and I can't seem to figure out why it sometimes backfires through the carb during hard acceleration. The motor was in the car when I bought it so I don't much about the internals other than it had a "soft rebuild" so I'm assuming it's pretty much stock and was just freshened up. I added a stock 4bbl manifold, a 650 CFM Summit carb, Mopar Performance distributor with orange box. New plugs, wires, fuel pump and fuel pick-up. Have tried different timing settings and adjusted the fuel level in the carb with little improvement. Suggestions needed! ](*,)
