95 GT - 55K miles - I have been fighting spark knock for years. I have done the following - Timing at Factory Spec - 180 Deg Ther - Oil Cooler - Cooler Plugs - Water Wetter - 70 MM TB - New ACS - Kenny Bell Ram Air Kit - Cleaned MAFS on Regular Basis - Run Premium Fuel for Years - Tried Octane boost, No Change - 3.73 rear gear - AOD Trans. Just kind of learned to live with it. Not too bad in winter. Pretty bad in summer. Recently on a trip I noticed something strange. I usually drive by foot and do not use speed control. At highway speeds if i use gas petal to maintain speed on slight grade - get subtantial ping. Previously did not use speed control for this reason. However, on trip I did engage speed control to rest leg and immediately noticed ping went away!!!! Why would engine ping driving by foot and not using speed control? Follow to previous post about brake noise. Have isolated noise to slop in pins where caliper mounts to bracket. Just thought I would let everyone know where this frustrating noise was coming from. Now Corrected. So Much better!!! Thanks.