Whats the biggest m/t drag tire I can fit on a 94 z28

I have a 94 z28. I'm running a 15x10 weld prostar rim in the rear. I was just wondering what's the tallest/widest tire I can fit in the M/T drag radial on the rear without doing a mini-tub??

Check the FAQ, the post about the Weld wheels. I've run QTP 28x11.5-15, and E/T Drag 28x10.5-15W's. The wheel wells had already been hammered for 315/35's. The E/T Drags required some trimming of the edge of the rubber bumper cover.