Switched to HEI

ABSOLUTELY open the plug gap; one of the big points of the HEI is to be able to arc across that larger gap. The longer and hotter spark creates a larger spark kernal which initiates the combustion process better, faster, and more complete.... more power and efficiency and effectively a small timing advance. You're missing a good part of the benefit if you stick at .035. My son and I put his 10:1 SCR 340's plugs to .045"; might try even more at some point. Man, does it burn clean....