What sort of advance are you running? Cooler intake air will help a little, but you are likely running a little too much advance. Unless you plan on moving to Texas where you can get 93 octane for about 50 cents less a gallon. I ran more advance(18, which is the max) without a problem, here I run 16 and have no problems, but I don't have cam gears either. YOu could always get some octane booster, or put some toluene in there, though I don't know how happy your cat would be with that stuff, probably all right, but I would not want to find out the hard way