P1SC Procharger - Serpentine Belt Size Recommendations

Howdy! I have a Procharged 1994 Mustang GT. I purchased a 2.90" pulley recommend by Reichard Racing to obtain my targeted 11psi of boost. What size belt is recommended. The parts store wasnt much help and I purchased one wrong belt size already. With the 3.55" pulley I had a Gates KO61145 belt and only saw 3lbs of boost. I believe the 1145 in the number represents 114.5" belt length. Please correct me if I am wrong. I measured the difference in pulley sizes and am guessing I need a 112.5" or 112" belt for the 2.90" pulley. Anyone have any input on this and a brand/part number for a belt at some of the common parts stores. Any assistance would be greatly appreciated. Thanks, Thomas a.k.a. T-Bone