A “low differential” is one with a higher ratio number, IE, 4.10 gears are lower than 3.55 gears.
The best way to visualize how the gearing affects your truck is to think about riding a ten-speed bike (or however many gears it’s got).
When you have it in 1st gear, you pedal like crazy, it’s easy to pedal, you don’t go very fast, but you can climb a steep hill.
Put it in it’s highest gear and you pedal very slowly, it’s harder to pedal, the bike goes fast, and it’s really hard to go uphill.
I agree with the others, low (4.10 or 4.30) gears aren’t needed for just a camper.
3.55-3.73 is fine. The engine will turn slower and you’ll probably get better mileage especially when the camper is off.
If you were gonna pull a heavy trailer I’d say get the low gears for sure.
