S&S Cycle Super Stock Big Bore Engine Cases For Harley Big Twin Built for Harley Big Twin engine projects, these S&S engine cases arrive with key bearing races installed and the pinion shaft bearing race pressed in and line honed, eliminating the need for additional line boring and honing. The 356-T6 heat-treated aluminum alloy construction features CNC machining and added material in critical areas for strength without requiring frame-clearance modifications. Features: S&S complete engine cases come set-up with the cam and sprocket shaft Timken main bearing races installed and pinion shaft bearing race pressed in and line honed, ready to fit Offers substantial labor savings and eliminates the need and expense of line boring and honing Cast from 356-T6 heat treated aluminum alloy and CNC-machined for consistently superior quality Additional material has been added in key areas for strength without requiring modifications for frame clearance Clearances for any stroke up to and including 5 with stock or beefy S&S rods Ported breather passageway/cavity optimizes oil scavenging efficiency while providing maximum timing specifications Crankcase assemblies include left and right cases, case bolts, nuts and washers, cylinder mounting studs, timing hole and drain plugs, assorted case fittings, sprocket shaft Timken bearing assembly, drive sprocket spacer and oil seal, pinion shaft main bearing race, cam needle bearing, oil pump drive shaft bushing and installation instructions Cylinder Bore Size: 3-5/8 Black powder coat finish Made in the USA