Gears are a can of worms. I did a lot of research before selecting the 4.56:1 gear ratio. As long as I have a Dana 30 in the front, I'm not going any stiffer. Selecting gears have a lot to do with engine size, transmission type, axle type and tire size.
4.56:1 ratio works great for the current set-up I have. 2.5L, 5 speed, NP231, Ford 8.8 rear, Dana 30 front, ARBs fr & rr and the Swampers.
A lot of the members have argued, that 4.88s are the only wat to go. I feel there is a stength issue with the 4.88s in a Dana 30. The pinion gear is real tiny.
You ask about 4.10s, Only if you have 4.0L and a automatic. I have a 4.2L w/automatic in my postal YJ. I run 4.10:1 w/ARBs in it.