Well, that depends on a couple other factors aswell. Axle gearing, transmission gearing (2.3L/3.0L tranny gearing is different from 4.0L gearing), and your definition of stock tire size.
Assuming 3.08 axle gears, 265/75/15s, and a 2.3L motor with IIRC a redline of 6200????
1st 49mph
2nd 83mph
3rd 122mph
4th 183mph
5th 225mph
Anyone have some input on the numbers I used?