S&S Super Stock crankcases are designed to meet the needs of today's engine builders. As stock replacement or for street racing applications, S&S Super Stock cases are made with the performance enthusiast in mind. Cases are cast from 356-aluminum alloy and heat-treated to T6 specifications. Although additional material has been added to key areas for strength, these improvements do not affect fitting in stock frames. S&S Super Stock crankcase assemblies include the right and left crankcases, crankcase screws, washer and nuts, cylinder mounting studs, timing hole and drain plugs, assorted crankcase fittings, sprocket shaft Timken bearing assembly, drive sprocket spacer and oil seal, cam needle bearing, oil pump drive shaft bushing and installation instructions. Shovelhead style cases feature primary scavenging port machining, accept a 1981-1984 style oil pump and 1970-2006 style primary. Evolution style cases are machined to accept a stock 1992-1999 style oil filter assembly and feature the same oiling and crankcase venting provisions as stock 1984-1992 models. Pinion shaft bearing is not included, it must be ordered separately. Bearing size depends on the size pinion shaft you are using.