I`m going to go with the 6.0 LS or 5.3 on this one. I've never been a "LS swap everything" guy, but they do make better sense in my opinion. No matter what kind of diesel you prefer, they are ALL big and heavy. Even the 12V/6bt. By the time you install a bigger radiator, intercooler, intercooler piping, etc... How much room do you have left? That tunnel in your floor might get quite large. Heck, even the old gasser in the COE trucks had updraft manifolds and carbs to make extra space. If you're looking at horsepower and torque numbers, the only thing a 6BT has over a 6.0 is low end torque. The 6.0 has a longer, higher RPM power and torque curve than the 6BT, in my opinion, it's the better choice. If you start looking at the 24V Cummins, things start getting more complicated, oh and like I said before, you'll be losing a ton of real estate. If you're looking at aftermarket parts and support, sure the Cummins is popular, but the LS is king of the aftermarket. Anyhow, my $.02, the 6.0 has the best of everything, towing, performance, aftermarket support.
