Slowly proceeding with my old Raleigh Super Course project, and I want to switch to a square taper BB. The bottom bracket on this SC is 70mm and 26tpi, so most replacement bottom brackets won’t work. Sheldon recommends using the original cups and adding an appropriate spindle. He recommends a square taper spindle with the designation “7” (as opposed to a “3” or “5”) on it as well as using 6mm bearings. The “7” spindles are scarce, but the Dura Ace BB-7400 Spindle is listed for a 70mm BB shell. Will this work for me? Or will I need a “7” sized spindle as Sheldon says?