Generally: an LRC runs at lower air pressure (50psi); an LRD runs at 65psi; an LRE runs at 80psi; an LRF runs at 95psi..and LRH etc, etc,,,..each "range" has a specific weight carry capability (lower psi load range carries less weight).
Hey zeus, I hope I don't confuse things too much LOL!
One problem we run into when over tiring a 1/2 vehicle is figuring what tire pressures to run.
As was mentioned in the first reply those super size E tires at probably 3500-3700 lb capacity are replacing a soft 44 psi P tire now now puts the wheels at the bottom of the load match chain.
How much pressure are those 1/2 ton OEM wheel rated for ??
If only 50-60 psi then not much is gained by a big heavy thick tire operating at low pressures.
This topic comes up often for 1/2 ton truck owners in the TT forums looking to stiffen the sidewalls or with a small 5th wheel trailer looking for more reserve capacity.
Many 1/2 ton owners who have gone to a big load E tire didn't like the handling mostly (myself included) because pressure was not enough to stiffen the sidewall because of a low pressure OEM 1/2 ton wheel. Some even sold their 20"ers and went to a OEM 17" tire/wheel.