mopar performance plug wires

would going to an 8mm wire or an 8.5mm wire from a 7mm wire even going to be noticeable?I'm running the mopar performance vaccum advance distributer with the 4 pin ecu made by wells and a borg warner select ignition coil.
I know i need to get a better coil and ignition module, i just dont know what to get, i was thinking the mopar chrome ecu and the mopar blaster coil. Or the mopar chrome ecu and a canister coil made by taylor, or a canister coil from mallory or crane cams.
I just dont like these borg warner select plug wires, i dont like anything made by borg warner, i think its garbage. At least there ignition products. I just wanna know if i would even benefit from an 8mm or 8.5mm wire. And i have my spark pluggs gapped at .035 should i re-gap them at .040? what is going to burn the fuel better .035 or .040? Say somone was running lean at an idle, would it help them to re-gap there spark plugs to .040 from .035 or would it just make it even more lean because there was a larger flame coming from the plug?