Coastie, have a real good think about why you want to do this.
Any diesel engine is going to weigh more than our lightweight V6, and will totally change the balance of the VX.
It will also be less powerful and have less acceleration.
I used to own a 2.8L turbo diesel Isuzu MU.
Good steady old rattler, but no show off when it comes to power.

Ok, it will be cheaper to run, but if cost is the reason for doing it, you would be better off buying a diesel 4wd in the first place.

Yes it can be done, but would you be happy forking out $10k and then finding you didn't like it??

Just my opinion mate - your car, you do what you want.

PK