ok, these responses lead to further questions.
I know very little about rear end ratio's...any explain?
I sense the half doors even as an option from new do not have tops either canvas or plexiglass?
The ratios (Rear end for the rear axle, front end for the front axle, etc...) are a way to describe the leverage the differential has.
If you ever rode a 10 speed bike for example, you might remember that in 10th, you could go the fastest, but, found it very hard to go up hills.
In 1st, you could easily go up hills, but might pedal like mad, and still be going pretty slow.
In 10th, you had a numerically
LOW RATIO, which, to confuse you, means you had a higher gear
For every revolution of the pedals, you'd get a certain number of revolutions of the tires....THAT'S the ratio you're looking for.
On the Jeep, a numerically higher gear ratio, such as 4.10 vs 3.73, is more like a LOWER gear on your 10 speed bike vs a HIGHER gear on your 10 speed bike.
So, with the 4.10 differential, you pedal faster to go the same speed, or have more engine RPM to go the same speed, than with the 3.73 differential.
That means the 4.10 has better leverage, and can pull "harder", but, requires higher rpm, as your ratio involves more pedaling and less speed.
The 3.73 ratio can't pull as hard as with the 4.10 ratio...but, gets better gas mileage, as it can pull with lower rpms at the same speed.
There is also a 3.21 ratio (The STOCK Ratio). This is the ratio you get if you DON'T get the trailer towing package, or at least click the little $50 box for 3.73's as an option. (Rubi's come with the 4.10 no matter what you do...)
2007 JK's used 4.10 instead of 3.73 as the trailer towing and Rubi gearing....after that, ONLY the Rubi's had 4.10's.
Some early JK's also came with a Dana 35 (D35) rear axle as standard, a MUCH weaker axle than the Dana 44 (D44) which later became the std.
(Something to watch out for if considering a 2007/early 2008...and which Jeep might slip into the line later as well if you're not careful...)
So - 4.10's pull harder than 3.73's, which pull harder than 3.21's....and, generally the harder they pull, the worse the gas mileage....as more rpm's are required for any given speed.
Hope that helps a bit!