Craftsman YS4500 Mower, Lawn and Garden Tractor

Briggs 31P977-0670-E1, 331877-0805, and 331777-0956. Kohler Courage SV600-0025. You cannot interchange engine brands, you will have to replace your engine with the same brand and model series. You will need to check your mower to see if you need a Fuel Pump or large (9 Amp) alternator to run the Electric Clutch.