Major upgrades GMT800, 06ish XL 2500

[Bigburb3500]

Still haven't defined your terms yet. A 'vette is PERFECT for some things, sucks for others.
Same can be said for a 2500 suv.

A 6.6L DuraMax would be pricey ... but the bang for the buck would be tough to beat, especially
if you figure out how to run it on alternative fuels.

Agreed but probably similar price to a 6L90 swap with accessories, no?

Looked it up and Nazty Nate on YouTube did a Duramax swap on his Yukon 2500 and I think his bill was about $15k all in?

 

[Marky Dissod]

For that he got a 6.6L DuraMax that can outlast the truck AND pay for itself in fuel and maintenance savings.

about $15k all in

So, about 1/4th the price of a new bubba with a 5.3L petrol V8?
I get that considerable time and energy have been spent to save all that money,
but $15k to swap an LBZ into my '02 Tahoe,
would likely last longer than any other used vehicle I could afford for $15k with comparable functionality.