Originally Posted by PsychicVampire
Not to hijack this thread (though it is related).....
Could you please explain what you mean? What would the 3.42 be better suited for and why and what would the 4.10 be better for and why? I don't understand.
Having 3.42 (3.42 turns of the pinion for every 1 turn of the crown gear) gears is better for constant highway driving as they keep the RPM down which will give you better fuel mileage overall. But it takes more time/power to get the truck moving. They will also have a lower tow rating.
4.10 (4.10 turns of the pinion for every 1 turn of the crown gear) gears are much better for towing (can handle much more weight) and are better for city driving as it is easier to get the truck moving. On the highway you will get slightly less MPG as you will be revving higher. They are also good if you plan to add bigger tires as it will turn them easier.
That's a really short crude explanation of the differences between those gears. There is lots of information throughout the forum if you want more otherwise googling something like "low gears VS high gears in a Dodge Ram" would probably bring up lots of results as well.