[Formulajones]

Originally Posted by 1968GTO421

Thanks for all the good info here as there is alot of confusing info out there. Back in the '60's we gapped everything automotive at 035. Then the '70's came along and 045 was THE gap to use. After reading this thread, I'm going back to .035 on the Pontiac. The late model cars I can't decide on what to do (like my wife's 2018 Ford escape with direct FI). Manual spec is probably best.

On the modern EFI stuff I follow the same procedure.

We were into LS engine stuff for years and had 3 SS camaros from 98-2002 as well as an LS swapped Blazer. Typical coil on plug high energy modern ignition system of the day. On all of those I switched them over to copper core plugs and .035 gap and daily drove that stuff for years and 100's of thousands of miles.
At that time many of the LS tuners and engine builders I was around were also doing the same thing, copper plugs and .035 gaps and sort of became a wide spread thing among the LS community at the time. Copper core plugs conduct electricity better and the tuners all seemed to like the tighter than factory gap. Haven't been into the LS stuff for years now but I doubt any of that has changed.