Largest tire/wheel width with 8.5 rear

[mobileaudio25]

I'm using an 87 cutlass 442 8.5 rear end. What's the widest size tire/wheel you can run without a mini tub or rolling the lip. I'm either going to run a 15 in 60 series tire or a 17 in 40 series tire. What back spacing and tire are you guys running?

 

[chevy2480]

8.5 or 7.5 makes no difference rears are the same measurements out of any gbody. I run a 275/50 and a275/60/15 with no issues with a 3.5" bs 8" rim. I had frame rubbing issues with a 4" bs