Army-

Yes, the transmission will bolt up just fine to the engine, but I don't know if the 722.1 and 722.3 box lengths are the same, nor if the driveshaft connection (tripod) is the same. You would have to come up with a Bowden cable lashup to replace the bellcrank arrangement you have now. Some variants of the 722.3 had a mechanical speedo. I don't know much about the availability of 722.3xx in Europe, but I assume there must have been some 300Ds there that had auto boxes ( but they may have had 722.1s?). The 722.3 is a better gearbox, IMO- the TC is less likely to fail.

Rick

__________________
80 300SD (129k mi) 82 240D stick (193k mi)77 240D auto - stick to be (153k mi) 85 380SL (145k mi) 89 BMW 535i 82 Diesel Rabbit Pickup (374k mi) 91 Jetta IDI Diesel (155k mi) 81 VW Rabbit Convertible Diesel 70 Triumph Spitfire Mk III (63kmi)66 Triumph TR4a IRS (90k mi)67 Ford F-100 (??)