hi
we have been noticing that there can be a lot of differences in the diffs ,ie the fins and lugs etc ,so it can be a case of trimming fins and lugs etc on the diff
also leave everything loose until you have all the bolts etc started then tighten all bolts a bit at a time ,this kit was done as a bolt in kit which it is but can be a pain ,as were trying to fit something that is bigger than standard into the beam,it had to be in this position for drive shaft align and prop position ,so just take your time and have patience as there are lots of people how have them fitted so they do go in,plus people who are having there beams powdercoated seem to forget this can add 2/3 mm on faces and holes etc and looking at yours you haven cleaned it off faces or out of holes

mark