The slot is in the top center line of the tube. On another note, jim carter parts had new oakie bushings just in. I purchased one and should get it by Friday. Of note, the od at the front is 1.72 and at the rear is 1.68, which is in concert with the nos bushings I have and the info from the chevrolee database exactly. They measured it while I was on the phone. Am going to pull the old bearings and get an exact torque tube id. Right now my guess is 1.5 to 1.6 inch. Will have a shop machine it close to the tube dimensions to get a good interference fit, but not so tight I have to force it and maybe do damage. Can't figure out why the dimensions differ if I really have a 37 rear end.