Motorcycle Repair: From tapered to splined, bikers choice, whem

Question
I am trying to figure out whem Harley switched from a tapered mainshaft to a splined mainshaft and how involved that upgrade is to make?

Answer
They started using them around 1991. There are kits out there to change them over to splined. Check with Bikers choice. You can find them on the web. Part number is 41-1442
You would have to remove the trans to do the work.
Good luck and happy riding
Mike