Ignore money as a preventative factor here. I just want to know what it'd take. If it's even possible.

I think it should be able to work, you might also want to consider the 4.2 V8 out of a wrecked a6 or a8, just for other possibilities.

However I want to keep decent gas mileage on the hwy if possible. I was mighty fond of the 32-33mph I'd get out of the 1.8T when driving the speed limit. Yes I know that's rare, but even at 85mph I was getting 26-27.

they are completely different motors