I have a 289 bored .040 with forged pistons with a decent cam. It has afr 185 with upgraded springs. Im using holley sniper with hyperspark dist. (Msds wires) I can only get it to run/idle decent @25 degrees timing. Still bogs down and has mainly exhaust backfires but an occasional intake. Anyone have any suggestions/ideas on timing/target fueling/target afr?