My '04 305/555 SRW 2wd is rated at 14,200 lbs trailer weight... but I'd have to have the truck EMPTY to 'legally' tow it.
GVWR is 9,900
Gross tow rating is 14,200
GCVW is 21,200 (I know this is not exact but I can;t remember the number off the top of my head. )