+1mm forged stroker crankshaft for the CY46 and GP460 engine. Increases engine displacement by 1.4cc to a total of 47.1cc. Increases exhaust port duration by 2.5° and transfer port duration by 5°. If you are using this with a stock cylinder, you must use 2 base gaskets. When using with our billet head kit, you can use our stroker dome that allows for a single base gasket and single standard copper head gasket.