The alternator was installed today. The pulley that was shipped from Lycoming is the newer LW 12227 model which has a different pulley diameter....so the belt that comes with the Plane Power kit was too long. After contacting Vans and Hartzell without luck.....I got the info I needed from fellow builder Rich Hansen who bought the same combination of components. What worked well for him was a Gates 3/8" x 33 1/8" belt model number XL7325. It was a great fit. I installed/safety wired the mounting bracket and hung the alternator. I followed Plane Powers belt tightening procedure and set the belt slippage to 11-13 foot pounds. The adjustment slide was then torqued and the remaining bolts were secured with .032 safety wire..