Welcome to Carnity @JamesBY !
The Pajero 3.8 is a fantastic off-road vehicle for many purposes and for driving in the mountains it can indeed benefit from the following:
- Bashplate and perhaps some added skid plates underneath to protect vital components.
- Good All-terrain tyres. Would not recommend to change the size of the tyres itself, as it's the 3.8 you have 18inch rims so you are limited already, unless you plan to change the rims then a 17inch rim with 265/70/17 would be nice.
-2 inch lift kit will give you a bit of extra clearance, which could be helpful in navigating boulders.
If you head out in the mountains in summer, the additional SPAL cooling fan for the transmission is definitely recommended, and during low creeping speed you will start to face overheating soon. In those scenarios it's better to be at home anyways
The Pajero has indeed a great traction control system for the mountains, so no need for a kill switch.
Deflate to around 25psi when you head into the mountains, it will increase traction significantly and dampen the bumps a bit as well.
In the winter we have the occasional wadi / scenic drive with the club, so would be great if you could join us.
Take care !