I think it'll be fine. You mention 3.0 gears. That exact ratio was never availeable. 2.97 or 3.21/3.23 were the closest. Tire size has a play as well. Do not go to much taller than stock. Yeild at 26 inch.
This is in a mildly rodded '38 Chrysler. The rear is a F*rd 8" w/3.0 gears. Tires are ~27". Wheel & tire size will probably have to stay the same as under the big, bulbous fenders there really isn't much usable room, and it would just look wrong with 14".