The S&S Super Stock alternator style crankcases are perfect for stock replacement and for high performance applications. Pre-clearanced for strokes up to and including 5". S&S Super Stock crankcases are compatible with stock 1970–'99 flywheel assemblies, primary covers, gearcovers, and clearanced for 38 amp alternator stators. 3-5/8" bore for 1970 - 84 Harley-Davidson® big twin. Natural finish.