I have B16AG1 Engine in my car.So far I modified Intake,header and Exhaust. For electricity I installed MSD SCI Ignition,Crane cams PS91 coil and Spoon sport spark plug wires. Also I have a fuel regulator set on 4.2 Kg/cm2. My question is how big I should gap my spark plug to get the best performance. I use denso iridium IK20. Thanks.