Cummins ISLe/QSL Piston Kit 4089963 Parts Catalogue Ref No. Part Name Part No. Required Piston Kit 4089963 6 1 Piston Pin 3950549 6 2 Retaining Ring 3920692 12 3 Piston Skirt 3966721 6 4 Piston Top 4941393 6 5 Piston Ring Set 4089644 6 Above is the introduction of the Cummins 4089963 Piston Kit, while if you need any …