I’d be happy to take you up on that, but I live out of state, well out of country. I’m up in BC Canada. If you have an excuse to be in Vancouver happy to go for a rip up the local mountains. I also plan to be down for the national rally this year if you can wait.
So my 110 originally came with the 2.5 NAD and LT77. I got a steal of a deal on the 300tdi, and it’s been great. I stuck with the lt77 which is a bit tricky to get to work right. I can’t hear the gearbox on the highway so not sure what the noise is you can hear. Tire and wind drowns the rest above 50 for me. As for it not being precise, there is a couple springs on the shifter that wear out. I replaced mine and once adjusted it’s just as good as an R380. Also the R380 isn’t really any stronger, and has a tendency to shear the input shaft. One other tid bit, by mounting the 300tdi where the 2.5 usually sat, it sits lower and further back than the stock location for the 300tdi, which I like as the 300 water pump is really high on the engine.
As for an LS3 or Cummins 2.8 they would both be great options, but yes you’d probably have to get stronger diffs, and then stronger axles, then cv’s, then drive plates. But then it would be great.