geez only cutting one side down 100mm, sure that got it right
when i did mine i cut the long side down 50mm and use the short axel in it, then cut the short side down 85mm and got the long axel cut down 135mm, and that was to get the diff 20mm wider than standard
and if you cut and re weld you should really get the diff straightened, i pressed the axel tubes out of my diff, cut them down and pressed them back in.....the hard way