I'm just wondering if anybody went to the same experience like I did. I installed a later ZF 915 LSD into my old mag case 915/06. I knew that there is a change from coarse to fine spine. Now I tried to install the fine spline drive flanges to the gearbox. Found out the they will not go in all the way without using a lathe to countersink a 5mm whole to both flanges. But what really freaked me out is that I have to take more out from one side compared to the other. Rougly 3mm difference. Everything is build perfectly. Why is this? Someone having an explanation for this?