Bill, If you have your AC number they can cross reference that on the computers (I work PT at Advance) and that will give you some NGK numbers. Believe it or not we still have books and catalogs behind the counters but alot of the newer/younger employees haven't been introduced to them. If you can get one of the guys/gals to pull the spark plug catalogs, they have lot of information about heat ranges and numbering systems. I sell a lot of plugs to racers, they buy several heat ranges and try different brands. I even go through boxes of plugs with one guy while he finds the ones that index the best for him. he is nuts.... But very fast... I will be at work tomorrow, PM me with some numbers and I will look up some stuff for you. I stock and can order the Autolite racing plugs if anyone needs them too.
Tommy (believer in the catalogs)
