The conversion so far has been bullet proof. In the interim I have swopped out the complete 3.85 diff to a 3.15 from the DCT. Again I failed to take pictures. I also managed to change the oil to the new spec LSD oil and the diff is much more qite.
The secret in matching the drive shaft is getting the correct components for your configuration. I would rather shorten then lengthen. In my case the rear is of the from a E92 M3 Manual the front section is from a 335 auto which had to be shortened ever so slightly. Remember my car is a auto so the gearbox might be longer in comparision to a manual.
08 E90 335i AT RB Turbos -NX Wet Kit - Chiplogic Flash or Procede V5- M3 Diff - AE Exhaust- Forge Dv's - Helix Intercooler - AR DP's - P3 Boost Gauge - Vishnu Meth- Stett Chargepipe and CAI