Yes, not confirmed, but I think you could use an X3 gearbox but it only address half the equation. The X3 also uses 3.64 ratio diffs. Not sure about the 530 xdrive, but my guess is yes once again.

It might be 6's, but I think the diff swaps would be easier and cost effective, and that is the route I'm going first. But you are right on in addressing the the actual gearing in the transmission. If you want to look into it and share with the group your findings, I'd be stoked. I do know from driving my wife's Manual X3, the gearing is much better. The ratios are massaged to be more car like and less truck like. 1st gear is still on the revy side but better.

I'm gonna have to go look up the specs on the 330xi now...........oh and welcome to the 3 pedal clan!

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2005 X5 3.0, 6MT, Alpine White on Truffle Brown, Sport, Preim, and Cold Weather, Alpina Stainless Headers, AFe Intake, UUC SSK, OEM 87's, 3.64 Differential Swap,Performance Modified Euro 2 Tune, UUC LTW Flywheel and HD clutch, Bilstein B12 Suspension kit
Future mods ZHP/Schrick Cam Shaft upgrade, Operation code name:Doppelschrauben-Kompressor

Wife's Ride: 2011 e70 X5 351 M///Sport.

Also in the fold: 2004 X3 3.0, 6MT, Black Sapphire on Terracotta, port, Premium, Cold Weather.