body vs driveline swap

[SICNICK]

I wanted to get as many opinions as I could on my latest project. I pick up a cherry 1990 Suburban. It's perfect in every way, EXCEPT it gets barely 12 mpg in town and 13-14 on the highway.

As long as I've had it, I've wanted to swap in a turboe'd 6.2 diesel. I just picked up an 1983 Chevy Suburban that also has a 700r4 and the a bad 6.2, BUT it has a banks turbo already installed.

So do you guys think it would be easier to swap the bodies of the two subs since my body is in much better shape?

Or would it be easier to take all the diesel engine components out of the older truck to put into the newer one?

Key advantages of each:

If I could easily swap bopdies, I could drive the beat up, old body on my current chassis/drivetrain, while building the other setup....

OR

If the body swap is too much, I could just transfer the diesel tranny, radiator, shroud, fuel filter, hydroboost system etc. Into the 1990, though this way I'd be without a truck longer...

What do yall think?