Looking at used '06 Challenger 34 TBH on the net shows a 14000 gvwr and ST 235/80-16 E tires (3600 lbs capacity) and 7k axles.
I don't know of any 16" Michelin tires with 3500 lbs + capacity for a trailer with 7k axles.
The only tires I would recommend for 7k axles is the Sailun S637 ST235/80-16" load G/110 psi at 4080 capacity.
This would require 110 psi rated wheels.
Or Goodyears G614 RST made in the USA comes in a LT235/85-16" load G at 3750 lbs at 110 psi.
Both tires are all steel ply commercial grade carcass made for regional service trailers. Both work great on rv trailers.