Motor likes between 11 and 12:1. My problem is that it has a tendency to go lean just before the end. Motor is not happy at 13:1 and leaner. I can actually feel it lay down a little just before the line. If I jet up, it is too rich every else. Also have a major lean spot between 1200 and about 2000 rpm ( lean readings you saw ). I'm sneaking up on that area with smaller hi speed air bleeds ( hoping not to make it too rich everywhere else). I usually launch at around 2200rpm. 3500 stall convertor. Wish I knew what I was doing.