i can put two soda cans in there end to end and still have over an inch od dish left. A guy who has a 64 falcon told me that short back space will let you get the wheels on and off. Not to mention i Love DISH. thats a pro street staple in my book
Built my first '69 Dart to run NHRA Super Street and did the same thing. Had 14x32's all under the car. Back-halved rear with Super Stock springs and coil-over front suspension. Car sat low, looked really cool, and launched straight as could be.
The only bad thing was the rules prohibited raising the stock rear wheel opening but did permit lengthening it. Had to lengthen the opening 4" to get clearance for the big meats. The Dart had such a short wheel opening that even with deep wheels like yours and the short backspacing, I still had to jack the car way up in the back and disconnect the rear springs from the shackles to let the rear drop enough to remove the slicks.
Hope you don't have the same issue.