Have any of you even know anyone who has attempted this? Is it even possible? I like the styling of the 99 rover discover, and love the reliability of the 300d Engine, seems like a good pairing. Any thoughts?

 

That would be very awesome if you can do that. Mercedes made a 2 door G wagon in the early 80's with a 617 engine.

I've seen a 92 500sl that someone put a 617 in as well.

Will probably cost you a bundle to do it, not to mention the smog issues if your state has any. (California is terrible with it.) With a car like that you may want to consider an engine that runs less like a tractor as the 617 does, maybe something more modern like a 602 turbo.