i have no experience with salisbury diffs and lack the pre load gauges to set it up correctly
So what you are doing is swapping the open centre from the rear of your Navara for an LSD centre.
So this means your ring gear will need to be transferred to the LSD centre.
The two important aspects of gear setup are (in order of importance) pinion depth (which determines mesh pattern) and carrier bearing preload (the tiny gap between the ring and pinion gear), or backlash as we often call it.
In this swap, we are not disturbing the pinion depth which is half the battle. Assuming the physical dimensions of the LSD centre is identical, we should not be upsetting backlash either. On this diff the backlash is set by adding spacers/shims either side of the carrier bearings.
I have done two of these LSD swaps now (plus my own). Measured the factory backlash, swapped ring gear over to LSD, reinstalled exactly the same, remeasured.. both times they were in spec which is a freakin pleasure. Although, both those time new side bearings were fitted as a matter of course.
My current vehicle used to have the C200 rear and one of the previous owners had put an LSD in. When I disassembled it, there were no side gear spacers or shims at all, the entire diff centre was floating in the housing, deflecting all over the place with approx 1/2" of diagonal movement on either side. God knows how long it had been like that for. The gears were perfect with no unusual wear after 285,000 kms.
What I am saying is that a) its a very strong gearset for a TD27, and b) if you disassemble the diff and carefully take photos & note the position/number of shims on each side, swap the ring gear over and reinstall it exactly the same, its quite possible it will still be within spec. To make the install easier you could freeze the shims overnight so they shrink slightly, then gently tap them back in, in the exact same order.
This way you should be able to get it safely installed and running, then to get the backlash professionally checked, its just a case taking it to a shop, of draining the oil and removing the rear cover.
Observations
-The side bearing caps are important, note their orientation and mark them.
-Don't mix up the old bearing races with the ones from the LSD centre. -Each bearing/race set is specific and should be individually marked
-Borrow a torque wrench from a friend for the ring gear bolts and side bearing bolts. Torque specs in FSM. Tighten in sequence.
-Park nose down on a slight downhill incline so gravity helps
Other observations
-Yes you do hear about C200s breaking but 90% of the time its the later 2000+ USA models running behind VG33s in the back of Xterras
-KBJJ has worn out a couple of C200 gearsets on 35s in the rear of his Navara but not broken them to my knowledge
-If it were me I would replace the side bearings on the LSD centre.
-I'm not saying don't do it properly, I'm saying eliminate most of the work and get it running within a safe range since its so easy to make adjustments in service.
someone give that man a pat on the back , the dicks at geartech told me my pinion needed removing , not a bad effort at scoring themselves a job but luckily im a cheap bastard and asked some questions first.