Fully machined billet steel camshaft and crankshaft sprocketsRoller chain designed with .250″ diameter rollersCrank sprocket includes three keyways enabling different settings: -4, 0, or +4 degrees of timingCrank sprocket includes three keyways enabling either 0 degress or +/- 4 degress of timingCamshaft sprockets are machined for and include a brass wear shim or a captive Torrington thrust bearing