If you notice the trailer industry (all types) don't use a wide base tire like a 265/75 tire for several reasons.
A 265/75 tire has a 8 to 8.5" wide tread which adds tremendous stress to the tire internally and bearings/wheels/axle U bolts and spring hangers as it side scrubs around corners.
I've never heard of a 8" wide trailer wheel with a zero offset. You sure don't want to mount a 265/75 tire on a narrow 6"-6.5" wide load baring std trailer wheel. Doing so balloons the tire tread.
Sounds like your trailer has 6k axle with LT235/85-16 E tires at 3042 lbs capacity.
As Me Again posted above you the Michelin XPS Ribs or the Bridgestone R250 both being a commercial grade all steel ply carcass LT tire work best on trailers with 6k axle.
Now if your wheels are rated to 3500 lbs capacity then the G614 or the commercial grade all steel ply carcass Sailun S637 tires would work fine.