Going with Ben on this one. All wheels just like tires have max load and a max psi rating for a reason. Granted some wheel mfg don't i'd their wheels with a psi. Give them a 1-800 or email for their input.
Split bead seats and cracked valley can be the result of over pressure or over loading. BTDT in my younger dumber days.
Fleet Ford specs show their OEM wheels with 2025 lbs up to 2400 lbs capacity. Most 1/2 ton Ford wheels I've seen are good for up to 65 psi unless marked otherwise. Exception could be Fords wheels for the F150HDPP which I've never heard owners say what they are.
I've used load E tires on 1/2 ton truck wheels but always went back to a P or a load C when they wore out.
The OEM P255/70-17 tires on the wifes 1500 chevy crew cab pulling a 10k lb car hauler with 8460 lbs on the trailers axles and pump the rears to 44 max psi......no handing issues at any speed or highway conditions.
P tire max load capacity comes at 35 psi although the psi may go on up 44-51 psi. The extra psi just stiffens the tires sidewall for towing/hauling duties.
If you go with a LT it has to be pumped to around 50 psi to carry the sale load capacity as the P tire does at 35 psi.
No more trips than your towing per year pump those P tires to the max when towing.