I have a 63 CJ-3B, completely stock. It has 29 inch tires on 16x6 rims. Does anyone know how much lift would be required to accomodate 32x9.50.15 super swamper tires on 15x7 rims? There are several leaf spring suspension lifts from 1-3 inches, and I will also upgrade the open shackles to some heavy duty closed shackles. Thanks for any help.