Land Rover Repair: 1999 disc 2 swap engines, driveshafts, driveline

Question
Can I swap a 4.0 with a 4.6hse and transmission or will i have to change everything including ecu's?

Answer
Yes, you can swap but you will need the driveshafts and mounts as they are different, and you have to make sure you swap in a 2003-4 Disco driveline as the one from a Range Rover is different.  ECU can stay the same but it can be reprogrammed with the 2004 4.6 software