outlaws are a heavy tire. Ai dont know about the 500 foreman but I had a slight problem in thick deep mud starting the 27' vamp on mine. But the 500's, just a guess, should be ok with some 28' tires. May want to be carefull of the width, that may be the hardest choice to make.
My next set of tires are going to be some 28' EDLs they are badd arse. But that will come after a pipe and some more do it yourself lift I think, cause the 27' vamps rub a little on the front fenders as it is.