Actually, mine are 26 X 10.5 on 12 inch wide wheels. Now, my car is quite low in the back - I like the look. Unfortunately, the billboards rub on the frame rails as well as inside the wheel wells, especially with a passenger
. I also had to fine-tune the panhard bar as well as make more room for the tire in the front of the rear wheel well by modifiying the inner panel.
I love the look of the B&B body - it actually looks more like an FIA 289 body with 427 doors. Problem is getting the tires inside the fenders. I have the Mustang II suspension with pin drives in front and I had to move the control arm pivots inboard about 2 inches. There is no way you can get the 26 X 8's under the front fenders without sticking out - they are just too wide. My entire suspension is highly modified. I ordered the frame with no suspension mounts and made my own suspension.
Sorry about all the bad news, but this is the time to address these challenges.
Brian