As fj12ryder says the LT E R-250 Bridgestones although a very good commercial grade tire simply doesn't have the capacity for a trailer with 7k axles.
All you need is a tire with 10-15 percent reserve capacity above your trailer 7k axle ratings.
The 16" G614 LT G at 3750 lbs capacity..
or the Hercules H-901 in a 16" LT G at 3750 lbs capacity...
There are several excellent commercial grade 16" ST G tires on the market;
the Sailun S637 at 4080 lb capacity...
the Provider ST at 4080 lbs capacity...
the Gladiator QR35-TR in a 3750/95 psi or a 4080/110 psi tire.
Tires above are recommended on RV and non RV trailering websites for heavy trailers.