i swapped over my gt motor to a markv111 motor. i used my stock wiring harness and extended everything i needed to. i lack a air intake and i used a mark 8 fuel rail and plugged off the return line. the car fires, gets fuel, and gets spark. it will hit everyso often and backfires through the intake. does anyone have any helpful hints to wtf it could be. im lost. im bout to get a dohc harness and computer and swapp that out if i have to. any help please. i pulled the plugs and they were really wet. i tripped the fuel pump and cleaned the plugs and dried them. then i tried to start it with starting fluid and nothing it would just backfire. same when running the fuel to it.