Motorcycle Repair: H-D 5-speed tranny mainshafts, shaft diameter, clutch basket

Question
I am in the process of changing the mainshaft from my '89
FXSTS. i have beefed up the engine and the the tapered shaft that holds the clutch housing has been damaged. What is the difference between the 1990 mainshaft and the 1991 and up mainshaft?? Puzzeled...Thanks

Answer
Geez Paul, I can't remember all this stuff.  I don't remember the difference.  Maybe shaft diameter and bearing changes.  The clutch basket and hubs are different.  The important thing is to know that 85-89 used the 85A shaft, 1990 used the -90 shaft and 1991 used the -91 shaft.  It's best to use all matching parts for one specific year.  Don't mix and match.  And don't think you can just look at the parts and see the differences.  Often you won't see the difference until you have everthing together and start putting the shaft in the case or installing a bearing or seal or putting on the inner primary and clutch and clutch push rod etc.