Td4 doner

I have a weird question. I recently bought a 4x4 2.5td auto Mazda Bongo non runner. I am thinking about replacing the existing engine and auto box with one from a td4 disco or Freelander. I am not sure if I will hit ECU problems or whether this is a plain stupid idea. The existing Bongo 2.5td engine is thirsty and suffer from cooling issues. Is this a really silly idea?

Anything is possible, if there's enough determination. However it'll be a lot of work, probably for very little gain.

Will the engine fit the existing gearbox or will you need to transfer that. Will the drive shafts fit if you do this. And the exhaust mods. Lot of hassle.