It depends on the flywheel you have. A 5/8" starter drive won't work with the multiplate flywheel, as the bolt head on the Bendix spring will hit the flywheel and jam the starter.
Do you know which flywheel you have?
Also which drive do you have? There is the original ABELL drive, and the replacement for it called the "SERVICE DRIVE". Both are for the 1/2" shaft and both work with the multiplate flywheel.
How do you tell the difference in flywheels, could you show pictures.