I use my truck for trailering 50% of the time.

I know how to calculate the load rating requirements for a typical car (car weight + accessories + driver/riders/cargo) plus some comfort room, divided by 4.

However, how do you factor in trailering? Is it predominately just the rear wheels, and then do you just factor in the toung weight? (so 600 lbs divided by 2 would mean an extra 300 lb rating per wheel)?

If those are the case, then a 2,470 lb (C) load tire is enough to handle pretty much anything you can safely put in- or on- a 1500... or is there some reason you need to go higher?

 

Stock tires are capable of handling the rated weight. This is why tongue weight is important.
Now, changing lanes on the highway or going down hill around a curve can cause a little squish in the sidewalls. If you want to be super stable, go with an XL rated tire. I wouldnt reccomend an E-load as those ride super rough.