285/85-16 would be 35x11.50. That won't fit without A LOT of work, which wheel is the least of your worries. Also, a 15x8 won't make a difference, you can't mount a 16" tire on a 15" wheel. Hello???
265/80-16 is a 33x10.50, do-able, but only if the backspacing/offset is perfect, otherwise you'll need a body lift and it still won't quite be right.
Brent