Wide engine bay, but I wouldn't call it long. I'm sure there are pics on the web, if not I'll take some this weekend. There's a fair amount of space between radiator and grill, and then it's still a mechanical fan, so it is not particularly long.
On a different forum it was pointed out that Toyota makes a pretty good 4.5L for down under. Granted it'd be considered underpowered at 202hp/317ft-lb in a 5,000lb plus truck; but I'd think it'd be a sweet setup with a proper 6 speed manual... I'm sure they could eek out what, 3 sales with a setup like that? me, someone else, and ... Problem is, it'd have a 3k tow rating then, since it's hp that allows one to fly up hills.
http://en.wikipedia.org/wiki/Toyota_VD_Engine
Maybe that 4.5L in the first gen Tundra, that might have been a nice setup.
While I want to be a Toyota fanboi and believe that all the issues will be ironed out, and it'll be a 500kmile motor... well wait, it's not a Toyota motor going into the truck, it's a Cummins. I don't follow big rig trucks, but it seems that when a maker wanders outside their typical boundaries there always is teething issues. I guess we'll wait and see, as always. Despite owning a diesel car, at the moment I'm not really in the diesel camp, mostly based upon TCO. Even if I much prefer a diesel ride.
I'm not a fan of the so-called third gen Tundra. I much more prefer my simpler older second gen, even if it's oversized and undercapable.