I say yes to 3/4 inch off the T.O. bearing retainer and no leave the splines alone. You can prove this by removing the trans and put some grease on the front of the retainer. Push the trans in until it can't go in anymore. See if there is a ring of grease on the clutch disc hub. Good Luck !!

Wanted Good Woman:
Must be able to cook , clean , sew , tune engines and polish trucks. Must have old Stovebolt and garage. Please send picture of old Stovebolt and garage.