OK, here are the goods. Casting indicates vintage 1987. The supplier (Competition Transmissions on eBay) had done the conversion to the 10 spline input shaft, bearing retainer and a general rebuild. It looks really nice and should install with minimal drama. Fingers crossed. Thanks to Lugnutz, I checked the speedo driven gear and see that it will need to change to a blue gear per his suggestion, a different tooth count I presume. The trans output shaft is 27 teeth, I have my local Napa counter guy checking on a slip yoke to fit 27T and my 59 driveshaft on the U joint side. I’ll post later part numbers for the yoke. Cheers.
'59 Apache ‘21 Beta 390RS ‘18 BMW R1200RT '12 Ford Flex '13 Aprilia Tuono ‘11 Ducati Hypermotard Salisbury, MD