Ok so i just replaced all spark plugs wires and the distributor cap also. It was running alright before now that i replaced these it backfires sputters and runs like crap. What could be my problem? I made sure that all the wires were run correctly and it just runs. Also does anyone know the best way to adjust the airflow screws on the 2 barrel stock carb. The motor is a 351 Modified. V8 Thanks!!