it's adjustment and likely slop caused by wear inside the shift box on the lower column - should open that up and clean it up, make sure the notches are not worn and the spring is sound - you prolly changed things a bit with the trans R&R -
see here and the next few pics
also note that as it ages the setup is prone to that problem if you're sloppy going thru the H pattern, don't "cut the corners"
Bill
