the 3.73 front diff does exist

[downforce22]

Most sites show that the early auto iX's had 3.73 final drives. Here is one front from an early auto car.

http://www.ebay.de/itm/BMW-E30-325ix-Allrad-VA-Differential-3-73-Vorderachsgetriebe-/141200306129?pt=DE_Autoteile&hash=item20e031afd1

With that said... Good luck finding a viscous rear.

Any chance you could take a us spec V3.91 or something and rebuild it using parts from a US spec 3.73S from a RWD car to make a viscous rear end to match?

[The Dark Side of Will]

Any chance you could take a us spec V3.91 or something and rebuild it using parts from a US spec 3.73S from a RWD car to make a viscous rear end to match?

Already had that done with U.S. market 3.64 gears. No reason 3.73's wouldn't work.

Nice find!

[nando]

the carrier on the ix is different but the ring/pinion should fit.

known about the 3.73 but never seen one before. I don't think they made too many early automatics.

[Northern]

Already had that done with U.S. market 3.64 gears. No reason 3.73's wouldn't work.

Nice find!

I picked up a 3.64 R&P from Haoming/Wangan just for this purpose. Just too busy to ever work on any of the cars.

[The Dark Side of Will]

I picked up a 3.64 R&P from Haoming/Wangan just for this purpose. Just too busy to ever work on any of the cars.

I had Markert set up a viscous rear with 3.64's and E36 rear cover.
I've been thinking that snagging a 3.64 front would help me phase the project, so I could do the full rear suspension with Z3M subframe before the engine swap.

I also have an E23 210mm diff that bolts to the E30 subframe, as well as the E32/E34 rear cover and E36 M3 CSL mount bracket to make it bolt-in for the 188 with e36 rear cover. I need to snag an e32 3.64 unit so I can get this franken 210 built up as well.