mini tub

Any one have info on a dart convertible mini tubs. I will also move the springs to the frame rails and use a stock axle. I assume I can run a 10 inch rim with the stock back spaceing. I want it to look like a stock rim just wider. What tire can i run? I was thinking a 325-50-15 MT tire. Does the convertible tub limit tire height . Do you loose much if the handling moving the springs. ??????