Cheater slicks?

Anyone know where to get a 28x9or10 x15 cheater. Im stumped. Coker, Towel City, Hurst, all make really cool ones but they are all over 28. I have been told that a 28+ will not fit a 68 Dart :violent1:.
The odd thing, my bf goodrich 275x60x15 are supposed to be 28 but they are only 27 1/4 on the car and i have 3/4 inches before the lip. Any ideas???
I have a real pair of Capital Cheater slicks that are in excellent condition. They are available to purchase if you are interested.