From Northern Tool:
Brake Band and Drum — 4in. Dia.
Drive Sprocket — 40 Tooth
Drive Chain #35
Hilliard Extreme-Duty Centrifugal Clutch — 5/8in. Bore, 12 Tooth, 35 Chain Size
I will have a used or harbor freight horizontal shaft engine, probably 5 hp or so. The frame is a fixed axle frame...