Incorrect............
If you change the final drive ratio in anyway the speedo will be out...

I do multi day back country rides on my XTR with no probs...

Well, I did it!
Land End Trial successfully completed (just over 400 miles and 24 hours door to door)
The XT didn't miss a beat (I did!!) and the whole experience was truly fantastic.
I would recommend this type of event for anyone with some off-road ambitions.
Not too many mods to the bike in the end (a carefully selected tool kit, enduro tyres, anti-puncture gloop, bigger back sprocket, hand guards, route holder) and it performed just fine.
I never managed to fit a bash-plate but I got away with it.
A great group of people (and a pretty bizarre range of bikes)
I'd post a photo if I could work out how!!

Sounds like the start of bigger things to come !
Glad to hear it all went well & you had a good time.