For the first years of heavy weight big twins (988 cc/ 60.3 cuin) the factory chose tu use a metric bearing. To compensate for minor production irregularities, they used a so-called double-row self-aligning ball bearing. The dimensions of 25 x 62 x 17 mm seem familiar to someone who feels at home in dealing with inches and feet. But these dimensions are just the tiny bit off of common inch fractures. So, for all ye restorers out there: dont look further, here's the right stuff.

The flywheel spocketshaft is no press fit in the inner race, but a slide fit.