As much as I hate to be Debbie Downer...they arent on it yet. everything is ordered and will be put on in the spring. is it gonna suck so bad that i won't wanna drive it?
You're in central PA where there are hills, lots of hills. You will find yourself downshifting - A LOT if you keep the 3.21 gearing.
With a manual and 35" tires, you might be better off with 4.10 or maybe even 5.13 so that when you tire of your 35"s (yeah, you saw what I did there) you can step right into 37"s and not really notice a difference.
Another route is to look for someone who is getting rid of their F/R Rubicon axles and work something out with them. Do that and you end up with lockers out of the deal in addition to the better gearing.
Some other things to consider:
Get a tuner so you can calibrate your speedo and odometer for the larger tires.
Trim the pinch seam by your rear tires (or slice your tires open on the first speed bump you hit.)
You may need to look at wheel adapters if your backspacing isn't adequate. You will want to keep the rubber from rubbing on your steering components.
Lifting the Jeep - since you didn't mention a lift, I wasn't sure if you had already planned on doing so. A 35" tire won't leave you much room for articulation.
If you have a 2dr, you will want to be mindful of how tall you want to go
Anything more than 3" on a JK means you will eventually encounter issues with your driveshafts.
Extend your brake lines or add relo clips
bumpstops to keep you from bottoming out the shocks and bending them.
Upgrade your shocks - new ride height means the stockers will no longer fit. They may work for a day or two, but I would'nt trust them any further than I could throw them