You can check out tdr1.com, Lots of reading and info for the dodge trucks. The era of the truck makes a big difference on temps. The Piston material and the addition of piston coolers make it a hot topic and temps have changed over the years.
I put the probe in the exhaust manifold back by rear 2 cylinders (hottest point). The 1200 # is really for the 12 and early 24 valve engines. 5.9 common rail engines run hotter due to egr built into the cam.
For the 6.7 the high EGT's are due to fuel being injected in the exhaust stroke and they may reach levels of 1500 Degrees to clean out DPF. The temps will be high from exhaust manifold to DPF but I believe its building some of that heat outside the cylinder.