bolts of the CMB to the frame. Some confuse these with washers and place them on the wrong side of the CMB to frame at reassembly. Also the CMB has oval slots in the mounting flange for side to side adjustment to get DS parallel to the tranny centerline as well as getting the 2 parts of the DS in the same straight line.
You are right when you suggest to reference mark all parts upon pull apart as is stated in the service manual.