boostedcoupe
07-28-2010, 04:58 PM
Alright guys i need some help with spark plug choice. The motor is a 331 8.9 to 1 compression. The heads are cnc ported protoplines. 76mm on 20-25lbs of boost on 110 octane fuel. We were running plain ole autolite 3924, not the AR ones. The car has been brakeing up in the higher rpm's, I know i have a good ignition box and coil so i am thinking plugs. They were gaped at about 34, Im pretty sure that needs to be closed up some but i am wanting to run a racing plug with a recessed tip. What do you think?