I've been running Autolite 3924's in my AFR's since I built the motor earlier in the year. Compression ratio is around 9.6:1. I've noticed my plugs were a little shiny on the tip of the electrode, which is described as glazing, and according to the Autolite book is "plug too hot at high speeds". ??????. Well, I went a different route and crossed a Autolite 3923 with NGK stock number 2756 (BKR6E-11). I put the plugs in today and have drove it around, haven't check them to see what they look like, but the car feels like it pulls longer/higher? Maybe it's my imagination. Anyway I was just wondering if anybody was running a step colder plug than AFR recommends as a starting point.
