Here's what I'd recommend as a rough guide for a 3500lb curb weight Jeep with a 4.6L stroker and a 5-speed manual tranny. Keep in mind that other factors also need to be considered.

27-28" tires: 3.07
29-31" tires: 3.55
32-33" tires: 3.73
34-35" tires: 4.10

Bigger wheels add extra weight, and extra weight on the vehicle itself needs to be compensated with shorter, numerically higher ratio, gearing (10% more weight requires 10% higher ratio gears than those quoted above). The extra aerodynamic drag at highway speeds induced by lift kits also needs to be compensated with shorter gearing.