Piecing together your own M20 stroker engine? This crankshaft sleeve is required to adapt the stroker crankshaft to the M20 engine. This applies to 2.9L, 3.0L, and 3.1L stroker engines. Available by itself or with a new OEM crankshaft bolt and machined OEM crankshaft bolt washer. This is the same hardware included with our complete stroker kit. These sleeves are made to our specifications and finished in-house.