I compared what Cadin's gearing X tire size to mine and the difference is dramatically in my favor (see attached image). The columns on the left are of the Jeep, while the Land Cruiser is on the right. The jeep has more mechanical advantage over the LC, so If he can move his rig down the highway, then I should have zero problems doing so as well.

I think your right, after looking at the variables it would stand to reason that timing is the major difference between the two rigs, the Jeep is set at an unknown amount while the LC I think is set at 25*?. I had had plans to time the IP when I put the EGT gauge in anyways, so we'll have to wait till time allows me to work on it.

Update:

Installed EGT gauge, looks like we are running in the 900F range.

Shut the jeep off one after a quick drive and heard bubbling coolant. Tore the engine down and just finished putting back together last weekend.

Replaced head gasket, water pump, thermostat, fluids, etc. While in there, advanced the timing an unknown amount, maxed out advance on the pump, but marked the old location for future reference.
Bought a IR temp gun, shows that the electric coolant temp gauge I have rigged up is approx 45F too high. Engine idles around 200-205F (Reading from the head vai IR) after a quick warm up run. Fans on.

The rear end has a leak and didn't want to burn anything up from lack of oil, will do more testing when I have a chance to fill the diff with oil.

Still seems like it should be running cooler than it currently is. Not sure what my driving temp will be. Didn't get it over 35mph.

Ideas?