Thanks for all the honest feedback gents. I think it would help to explain what i am trying to achieve with all these upgrades before going any further.
Here in Lebanon, its impossible to own a new Defender (even while they were still being produced) due to the ban on diesel vehicles. Only the Lebanese army, UN, and/or diplomatically immune embassies of other nations were allowed to bring in and register such vehicles.
That leaves us commoners with slim pickings. A defender is about as exclusive as it gets in a land where every other soccer mom is driving around in a 2017 G63 AMG...which cost $350k USD here including taxes and registration. The only choice we have is to try and find a relatively good shape defender from the days before the diesel ban and work on restoring the vehicle.
If i could...i would go buy the most up to date Defender diesel motor, transmission, ECU and dash to make it a true factory spec vehicle. Since that isn't an option, I'm starting to play with all types of ideas. One of which is the LS3 motor mated to the auto transmission. At least my wife would be able to drive the car (she loves it by the way ). If i go ahead and modify the motor and transmission, i'll most likely upgrade the ECU and pop in the new dash with modern dials and electronics. My goal is not to make the car go crazy fast or handle in the twisties. I just wanna make the car modern and reliable.
I would likely go for the more practical detuned motor option if available.