1061975
What axle gears do you have now?
The ratios available for the stock D30 and D35 axles are 3.07, 3.55, 3.73, 4.10, 4.56, and 4.88 :-D
The easiest and possible cheapest method is to find a used set of TJ 4banger axles with 4.10 gears and swap them straight in. Can be easier than setting up two ring and pinion sets.[addsig]