So I recently installed a 370z nismo tech diff in my 350z (yes it fits, just use the 370z axle bolts or buy new ones). It has a 3.9 final drive. install went smooth beside the axle bolts the 350z bolts are to thick near the head side(new ones from ace). Anyways after 7 hours of work and stress me being anxious to finish I over tighten the rear diff stud, now it just spins with out tightening at all. Is a new stud simply the answer or will I need a new cover(still have my Oem open diff). Any help would be appreciated! Thanks!