This single

Congratulations

because the brake pivot will be on the wrong side

They are coped at 1 inch to fit standard size frame tubing

Crankcases 1941-1947 Harley-Davidson Knucklehead - Replaces OEM #24520-41 Thread Size_3/8-16 This singleReproduction crankcases which meet or exceed highest restoration demands. Cast from state of the art materials and machined on CNC equipment for strength and precise fitment. Intended to work with stock or identically constructed engine components. Finished and detailed like the original counterparts so these cases will smoothly blend into your old mill to give it a new life. For ease of installation both case halves are carefully matched and feature