Read my plugs, was carbon fouling on 93 pump gas but not on 96 vp?

Oxygenated fuel vs non oxygenated fuel along with race gas vs pump gas will all require different tune ups. You cannot compare them to each other. For example, on the dyno running my twin turbo big block, pump 91 California junk gas vs sonoco 110 was a 2 jet number change in the front and 4 jets in the rear to maintain a similar afr. When you changed fuel you changed your required tune up. And you must have changed it for the better.