You can fit a 295-50-15" tire underneath with no modifications to the body IF you use Air Lift's rear airbag kit ($70.00) from Summit Racing. Mount them to Weld's Draglites (15x8 with 4.5" backspacing) or Pacer's version of the Draglite in 15x8 with 5" backspacing (PM MOB from this website as he just got these and they look identicle.) I have the 4.5" backspaced 15x8's on mine with the 295-50-15" tires and wish I got the 5" backspaced model (Weld doesn't make them and I wasn't aware of Pacer's version until I saw MOB's. I didn't have to roll the outer fender, nor beat the inner quarter panel at all.
At the track, I run 26x10.5" E.T. Streets on the same rims.
Here's a pic.