The 7.3 PSD was used in International applications as the T444E with changes. And the 6.0 PSD is used also in some Internationl applications.
Saying that they are the "same" is an over simplification. The foundations are similar, but even the emissions that both are required to meet have differences. NO2 emissions are different on light trucks vs medium trucks and other things.
There are many opportunities out there. Cummins makes a nice motor too.
Hey, Brian, what are you trying to do exactly?
For me, my diesel offered me several initial opportunities. First, economy. I costs me less in fuel, and the maintenance issues have been dramatically reduced. Next, my chassis just handles the towing better.
Bonus was that I got places faster because I can get up to speed and even pass better with my simple 475 or 525 ft lbs of torque...(bus doesn't have an intercooler, so they are detuned that way...still, more than enough power for me even with a bigger trailer now). I could drive faster, but it's too gamey in traffic. I didn't like my intial ground speed at the specific RPM that I felt I needed to tow at for my power and fuel consumption rates. Changing the rear end was gonna jump my dually axle up too high, so I just changed my tires to get a bit more ground speed.