Still missing some infomation, but my best guess  from a long way away, and a totally different set of life experiences, is  that  you have a total weight  of somewhere around  12,000 pounds.   

12000 x 65 % / 2   says  that each tyre needs  to support 3,900 pounds.  

 Hawken Cougar's suggestion to go read the sidewall is likely  the best advice you'll get here.