[Paulryder]

I installed an AEM X-series Universal Exhaust Gas Oxygen (UGEO) gauge so that I can set my air/fuel ratio on my 1966 GTO Tri-Power center carb for the best power and torque. Initially I set the idle mixture screws so that I had a reading of about 14.6. I have since backed the screws out to 5 and 1/2 turns and the lowest reading I can get is around 13.3. I would like to get to 12.5 or so for the best power. Once I tried going any further out (to 6 or 6 and 1/2 turns), the screws feel pretty loose and the mixture is not changing anymore. Is there something else I need to adjust or change in order to get a richer mix?