I currently am running 15 inch american racing outlaw wheels with BF goodrich 31 inch tires.
I want to keep the same tire size but thinking about some bigger wheels. What are some good tire/wheel combos?

 

To try and keep close to your 31" tires you could go with a 265/65/17 if you find a 17" rim. I'm running 265/70/17's which physically measure just under 32" tall. That's with 17x9 Camaro SS wheels from a 2002 Camaro. Since you have a ZR2 you might be able to do this combo without any modifications. The Camaro wheels have 6.8" backspacing, so on normal Blazers they need spacers on the front to move it away from the frame and sway bar. It's a bit of a pain, but I love the wheels and the look my Blazer has.

 

I really like the backspacing on my wheels now because it sticks them out and gives me a cooler stance. the tire size is what I would keep I think I want to just change my wheels out.