Hi all,

Some background on my car - intention is a primarily daily drive with the odd track day or two every year. I intend to S54 swap it eventually, and am trying to decide on direction for certain areas, and thoughts on what I should do. It was originally a stock 325i auto. It has had some changes over the years, and as it stands it is as follows:

GS6-37BZ Manual Swapped
M-Factory 1.5 way LSD in 3.46 gearing with completely new bearings and seals

I would prefer to keep the GS637BZ and the diff as is, and I believe the measly torque out of an S54 is perfectly manageable for the non-M drivetrain to some degree. All the anecdotal evidence I have seen doesn't move the needle from the 'No evidence which way' part of the scale.

My questions to you all:
Will the rear end hold up? The diff is rebuilt, gears were good, the LSD centre is used with 335s/135s autos/DCTs (one of them)
Will the axles hold up? Anecdotal evidence with people running ESS TS2s and so forth suggest the possibility.

I have three ideas:
Upgrade to M3 rear end, and having to replace all the bushings I have just put in the car.
Upgrade to 330/ZHP RTAs + manual axles if possible, but autos if nothing else. (I can reuse all the bushings in the car.
Custom axles.

I want to avoid the M3 rear end as long as possible. I don't want to have a custom driveshaft and have to sell my LSD for otherwise unknown condition parts.

the 330 axles seem to be the logical option if/when the 325 axles break.

Custom axles is a likely good option too, but probably the most cost inhibitive.

Thoughts?