Rich, it occurs to me that since y'all are in the area and since you've noted a bit of detonation with your Shelby I thought I might mention the 76 Gas Station at Foxworthy and Almaden. 100 low lead. I run a BSA Spitfire at 12:1 that likes higher octanes. I've been out of town on a business trip for two years now but I researched the net to see if there was anywhere else. I found a discussion on a Corvette site.
http://forums.corvetteforum.com/show...23&forum_id=45 Good Luck, Scott