Diesel conversion for 1991 RR

Looking for some advice for "those in the know..."
I live in Costa Rica, where parts and good maintenance are a hard bargain! Anyway, I've recently acquired a 1991 RR that has spent half its life parked. Surprisingly, it fired right up when I put in the new battery. Has 150k miles and runs ok, but I Am seriously considering changing out the petrol engine and automatic transmission for a diesel & manual trans. That is exactly what we need for the conditions down here.
Anybody had experience with this???

If you insist, a 200 tdi disco motor and an LT77 box are the easiest and cheapest conversion that will be reliable and cheap to run/maintain.
Nuts/bolts job - all you need is a rusted out Disco.

OK....thanks.
That's something to look into...

Not wishing to hijack the thread, but I've been considering swapping the current V8 for a diesel unit as well (just idle thoughts at the moment, maybe something to do in a year or so).
The only thing is that I'd still want the same grunt that the 3.9 V8 gives whilst getting more like 25+mpg instead of the usual 18. Talk about having your cake and eating it!

I had thought that a 300Tdi unit with some chip tuning on a rolling road might get close to this, but I'd be open to other options and would welcome any advice anyone might have.
Maybe LPG is the way to go instead?

I know the 'sensible' option would be to sell my beastie and buy a Tdi one, but with the work I've done to it already, I want to hang on to it.

There's lots of good reasons to swap out engine and trani; all depends on how you use the vehicle. If your car is running fine, and you use roads that are mostly paved and in good condition, do you really need to change a thing?

For me it breaks down like this:

1. 50% of the driving time is off-road use- pure mud, dirt roads,rocky roads, or soggy creek bottom. All in mountainous territory.
2. Numerous water-crossings
3. Abundance of "cheap" diesel compared to gasoline
4. Labor, as well, is relatively cheap

and there's some cons, of course...
Nobody here can work on an automatic transmission
Nobody here can work on the Rover V-8; so the engine never really runs "good."

OK, what I really need down here is a Hummer. Yeah...the ultimate off-road vehicle. But I've got the Ranger, so that's why I'm looking into diesel.