The 300Tdi is the best motor in an older Defender. I had that same motor in a 1995 Discovery 1 that I bought new & kept for 20 years. It was great if a bit underpowered, but would cruise all day at 70mph.
It gave the vehicle a good range but only had a 88 lt. tank. I never got around to fitting an aux. diesel tank in it unlike my current 2014 TDV6. The ONLY mechanical issue I had in the old Disco was with the
manual gearbox when I did a bearing on the main shaft & destroyed 3 cogs - it still got me 200 miles
home though!! Good condition low mileage classic Defenders are impossible to find on the market here
They're as rare as good '65 Mustangs or 1960's Ferrari's here in Oz. We'll never see such vehicles from LR again - same as D3's & D4's. Body on frame - a great chassis to mount anything from the aftermarket gear fabricators. I'd suggest new Defender buyers should order up ALL of the offroad options available as it may be impossible to fit gear to them later - like "soft" D5's.