I think a 4.6 swap would be the "cheapest" reliable way to some extra hp. I think the Rover V8 engines have enough issues with over heating and blowing the HG & slipping the cyl liners to bother with risking a super charger. Check out this linnk for some hi-performance rover V8's that are natrually aspirated. 300hp & 350ft/lb torque would be nice, better buy some new driveshafts too LOL!

http://www.rimmerbros.co.uk/rimmer/l...scovery/eng-v8

 

I put some headers on mine. http://store.summitracing.com/partde...p;autoview=sku

They fit without modifying them. I did have to bent the starter heat shield and the knock sensor on the drivers side. Also had to lift the engine with a lift to fit it on the drivers side. Had a local shop redo the Y-pipe (about $150). The top end is MUCH better, overall a bit faster.

Also, I recently removed the plastic piece in the airbox that goes to the fender. Its the piece on the airbox itself, not the oval pipe. It was a pretty big restriction. It has better pickup, but I can't use a snorkel without putting it back.

 

Throw in a bored out 5.0 http://toddcosuspensions.com/landrover50ho.html

 

I also have to ask what part of Idaho are you going to be doing the driving in? I have driven my 2000 up to Salmon and over to Jackson down thru Kemmer and etc. Never once had a problem with being able to pass somebody on the moutain pass up to Jackson. Though you have to plan for it and these trucks do go from forty to sixty in a decent time. They are not going to win you a race but they can get you around in the fun snow they get.