High RPM Backfire when fully warmed

TheGrimSpeed said

Do you use a stock style cap and rotor just upgrade cables? And open plug gap to .045?

Click to expand...

Same cap, rotor, and plug wires. I didn’t even touch the plugs. I’ve seen plug gaps tested from .020 to .100 on the dyno make zero difference, so I don’t worry about em. Mine I think are .035 currently.