I took the trip down to indy yesterday to help my sister rebuild her house. Every time I let off of the accelerator my engine (454) would backfire quite badly. Luckily the trip was at night and I could go almost the entire way without altering my speed. If I let off the accelerator very slowly I wouldn't backfire very much. But it is popping now even at idle (at least it was after the trip, maybe now that it isn't so hot it would be alright). I really don't know what causes backfires other than timing, I have new adjusted points, recently adjusted valves, new timing chain and recently adjusted timing.
Known problems, exhaust leak at head (bad bolt hole), choke is stuck open, air filter housing pinches throttle body (I have ordered the spacer).
Thanks a lot
