Re: XH XR6 engine into a 3spd auto EA - whats involved?
Most XH’s didn’t have the variable intake manifold – the XR6 did though. I’d expect the engine mounts should be ok since the front end of the XG & XH was rejigged to take the 4.0 motor, not sure if the bolt pattern on the tranny changed but hopefully not. Have a look for other threads where people have converted from 4sp autos to manual as they have the same issue as you with the 3sp having no computer. Try & get hold of wiring diagrams to compare to see how you will go hooking it up. Good luck!