Its time to get the car out of summer hibernation and some fresh plugs are probably in order so wanted to get some thoughts on whether to go with what I have been running or go with something else. Currently running Autolite 23. Motor is a 10.5:1 451, OOTB Edelbrock RPM heads, I'm limited to 91 octane at the pump. Cam is a solid .520 lift @ 254, 800 Edelbrock carb, Firecore distributor, chrome box, MSD Blaster coil. The plugs look clean now and if anything maybe on the lean side.