m57 conversion in 90

hi I have got a 1988 90 with the 2.5 petrol engine (17h) block has hole in it. I also have a bmw m57 engine with only 30.000 miles on it I would like to put it in the defender but make it auto as I am doing it for my friend as a present. and they can only drive autos I am a little stuck on what I need for it i.e. what gear box I was told possibly a GA6H26Z. and can I use the Land Rover transfer box etc also about wiring how to put the ecu's etc and the keys/immobilize and the gauges i.e. speed fuel coolant etc thank you

Thats a lot to sort out for a friend.
I would be contacting one of the engine conversion specialists for advice.

If that M57 is sitting in a complete vehicle, then you're already halfway there in terms of moving wiring looms, ECUs and electrics in general.
With regards to mating the transfer case, you have the option of machining an adaptor plate and intermediate shaft to allow you to bolt up the transfer case to the transmission.
Basically it's possible, given the time, resources and level of skill.

Have a look on YouTube at Olly's channel- Sixth Element Engineering. He is a friendly guy and has recently done this conversion. Juice motors are also doing one right now, but not without problems.

Hi thank you so much all the help much appreciate