This is my build here: https://www.landyzone.co.uk/land-rover/200tdi-s3-88-pas-long-travel-suspension-rebuild.298104/
Having also got another 200Tdi powered Series, I'd also suggest moving the alternator to the other side of the engine. Gwyn...
As it stands, £200-500 really, but nobody is likely to accept that. The chassis and engine are worth money on their own, but obviously require work to get into individual bits. As a rule, parts will often add up to more than an entire vehicle.
A...
Do you know what the exact failure was of the previous two diffs and what bits where actually replaced?
The front axle has many components, the diff is not normally a wear item and only really fails or breaks under duress of extreme off roading...
Are you in the UK? With no rear prop, do you have this declared as a modification with your insurance? Hacking the rear driveline up may well be boarderline on if it is truly roadworthy or not. Fixing the vehicle is really the best option or...
Also worth noting that the TDV6 was used in lots and lots of vehicles. Loads of Land Rover products from a D3, thru FFRR, RRS, D5 and Velar. But it was also used in a whole heap of Jaguars too, as well as Ford's, Citroen's and Peugeot's. And is...
Yet I don't think there has ever been a case of a remap causing the failure. It also isn't that the engine isn't strong, there is just a potential issue in the design.
Factory examples produced up to around 300bhp in some models/regions.
R380 stumpy is mostly a direct fit, it was intended for warranty use in the switch over from LT-77 to R380.
https://ashcroft-transmissions.co.uk/product/short-bellhousing-r380/