Westlake comes OEM on several types of trailers and they have about the same bad reputation as other cheap ST tires on heavy trailers. Their also sold at many of the local feed store or farm and ranch stores.
For large heavy trailers I would recommend upgrading to a commercial grade LT E at 3042 lbs capacity on 6k axles.
If you have 7K axles the Goodyear G614 LT235/85-16 G load range at 3750 lbs/110 psi or a commercial all steel belt carcass Sailun S637 LT235/85-16 G load range at 3750 lbs/110 psi.