Following ordering my rear discs for Dana 44 diff I have found a difference. The original discs where stamped C20326 so looking through parts catalogues ordered some Brembro which should match.
The inspection hole to tighten the brake calipers is located from centre od 121mm and not 110mm . The correct part no is JML731. I found a reference on an American parts site. So never take catalogues as gospel. All.cross reference and a number of categories have this incorrect.