Maybe it's too late at night, but I had a hard time following this thread.
The OP had problems with 245 size tires. Asked for advice, then went back and got the same problem size tires????????????
Is it correct that the 245 size is rated at or about 3100# per tire????
Hmmmm. My old truck weighted just over 7000 pounds --- about 4000 on the front axle and 3000 on the rear. Assume the OP has a similar weigh distribution and he slaps a 3500 pound camper on the bed. That comes to a 6500 pound load sitting on tires rated for 6200#. Oh yeah. There is the cargo trailer tongue weight as well. Perhaps another #200 pounds?
So, a 6700 pound load is riding on 6200 pound tires and the tires are supposed to not be a problem?
Please correct me if I missed something. Thanks.