If I remember correctly, the flanges are 10mm threaded holes. The 2002 inner CV is for an 8mm bolt, as you know. The 320i inner CV has the larger holes, but a spacer is still required (flange to flange on the 320 diff is less than 2002). I did this exact mod (320i CV and 3.91 LSD) and had to get the spacers from IE to fit it all up tight. I thought, incorrectly, that changing this inner CV would solve all the world's problems. No, only in my own little world. The bolts need to be the correct length, as well, to get through the axle and spacer to the diff flange. I can't see any reason you can't bore out the holes on the 2002 CVs, carefully. I'm fairly sure you don't want those bolts moving around after installation.