Engine Upgrade.

[DRTYFN]

So, I've been patiently waiting for a definitive date on either A) the H2 Duramax, or B) an H2 Alpha with a newer engine. At this point, I'm not holding my breath on a redesign(haven't heard any more whispers about it through the grapevine). I walked into my dealer's(Vic Alfonso Cadillac/Hummer) showroom today and took a peak at the new Escalade. Decent Luxury rig, but definitely not my style(boyeee). But what caught my attention, and got me to thinking, was the new engine - 6.2L 403hp V8, 13/19mpg.
It shouldn't be too much drama to put that drive train in a new '06 H2, should it? As long as there's no major wiring harness issues, that is. Should be same dimensions and attachment points.
Any techies have any insight into this?