i have been working on a 73 k5 blazer that i put a engine and trans from a 94 3/4 ton chevy tbi 350 with a nv4500. i replaced all wiring with a painless wiring. i get the truck to fire up and idle but if i rev past 2k rps it bacfires really bad or if put it in gear it stuble backfires and shuts off. i replaced distributor cap rotor wire and plugs no change.if i put a 3.9k ohmresistor in the a and b pin slots on the adl hookup truck seems to run fine and i can drive it without backfire or miss. so i am here to see if i get some more troubleshooting ideas.