there good motors all about the same in power..the jackshaft i ended up haveing a mechine shop make a chromoly one ,used a stock keyway for the secondary clutch, then another keyway for the front sprocket, turned down a coupler they sold and turned out a sprocket and welded them. but u need to figure out were the motor will sit and the jackshaft will sit then u can measure from center of of jackshaft to center of front clutch or crank to find a belt to fit correctly any snowmobile shop can cross reference the mesurment. and make sure ur secondary clutch will have the room for belt deflection and can open up without hitting the frame..sound fun..oh ya u can ues the stock jackshaft bearings also..