.060" gap is pretty standard on later model GM cars now. I have a vortec ignition with the "crab" style distributor, and with the stock gap, Im having LOTS of corona discharge. The entire ignition system has a faint purple glow around it when the engines running. The spark plug wires (MSD super conductor) also have the faint purple glow, and emit small sort of static electricity like sparks when I run my hands over them, or when they get close to the engine. Theyre not leaking. This is instead from the high E field around the small conductor in the wires.

I replaced the distributor cap with an OEM BWD one from the autoparts store after my Accel one wore out, and it didnt last more than 10 miles. Literally. As soon as I hit the gas, the #2 and #3 cylinders dropped out from internal arcing in the cheap-*** cap they have. I ordered another Accel cap since they seem to last, and switched back to the AC-Delco small tip iridium plugs. The small tip should allow a lower breakdown voltage, but, I think Im still going to have issues.

Should I just switch back to the .045" gap like the old HEI systems? Is there even a noticeable difference? The .060" gap works great for performance, but the voltage seems too high to be tolerable over the long term.

 

Yeah, I'd back them down to the stock gap. Once the fire's lit, it's lit. More gap only serves to hasten the demise of ignition parts.

GM used to spec an .060 or .065 gap on some engines back in the 70s shortly after the HEI came out. They retreated from those big gaps not too long afterward. And those were smogger 8:1 compression engines with very low cylinder pressures.

 

Actually, I think it was the spark plugs all along. I split the cap open where the short should have been, and it was fine. No tracking. For yucks I measured the resistance of the plugs (Champion resistor type), and they where all over the place. The one that was completely fouled out was 50 kOhms while the cleanest was 10 kOhms. For reference, all my junk-box AC-Delcos where 4.5-5 kOhms. Guess those 2-dollar spark plugs arent so good after all...