Disco 300TDi into 1987 90?

yup, im with adz on this one, personally i would fit a 200, but i aint a fan of electronics like the late 300's. the exhaust downpipe is different and sois the turbo hose. you can buy kits to mek em fit or you can manufacture the bits yerself, depending on yer skills and the rear axle has discs on it as well

Cheers for the replies, another question I've thought of.

If I do see a disco going cheap locally and go to have a look, and find the transfer box won't go into low range or difflock (as I believe some of them stick through lack of use) should this put me off, or is this relatively easy to fix?

Realistically this wouldn't be for at least two or three months, as I want to get a lift kit and some decent mud terrains first, and pay off a chunk of my insurance (being 18 the cheapest quote I could find was £1500, my mum got it on an interest free credit card but I still owe £1400 of it!). So finances arn't sufficient yet. But hopefully before the end of summer!