Getting another Jeep, maybe.....

Here is what I have found so far having both a TJ and a JK.

1. Thoughts on the 3.8 motor in relation to the 4.0? Does it perform about the same?
No. The 4.0 has a more torque and it is noticeable on the highway. The 3.8 is a higher revving engine but has worked well for me on and off road. I really wish it had more power though. Fuel economy is "OK" in the V6. Not that this means anything to most people but Off road, I prefer an inline 6 over a V6 because in a flop, a V6 will fill at least 3 cylinders with oil while an inline will most likely be OK depending on the angle. I don't plan on wheeling mine much.

2. What's the magic lift height that you start needing to worry about custom drive shafts and SYE on a JK Unlimited Rubicon?
You don't need an SYE on any JK. They are all fixed yoke now. Mines not lifted and I don't know much about lifting JK's but the longer base and ability to run bigger tires with smaller lifts make me pretty sure you are ok with a stock shaft. Don't hold me to that.

3. If I'm looking to go 35's, how bad am I going to want to regear? I know when I went 35's on my TJ (4.0 auto) is was pretty much a must do for me.
If you go with a Rubicon, you will have 4.10's stock but you will still want to regear because the 3.8 can seem like a pig (see response #1) on my Rubicon with stock 32's.
I'd say go to 4.88's.

4. what's the right lift height for 35's on a JK Unlimited Rubicon?
Once again, not 100% sure but I've read 2.5" to 3" is good for 35's.

5. I remember hearing something about leaking issues on the factory hardtop when they first came out, anyone know if that's still a problem?
Not a problem at all.

5. Anything else I'm not asking that I should know?
I can't think of anything right now. After 29000 miles, I am still very happy with my JK. I bring a family of five all over the place with it. Beach, camping, etc. I don't think you'll be disappointed.

Here is my thread that shows some of things that are, in my opinion, improvements on the JK.
http://www.delawareja.com/forum/index.php?topic=25995.30

Quote from KnoxRents

After 29000 miles, I am still very happy with my JK.

Except that darn front locker. Have you ever figured out if that was part of a larger issue (many vehicles) or just yours?

Quote from Quantum73

Except that darn front locker. Have you ever figured out if that was part of a larger issue (many vehicles) or just yours?

I searched and searched for the problem and the only other one was someone that transplanted a JK Rubi axle into a TJ so I figured that was a fluke.

The dealer hadn't heard of it and there were no TSB's at the time. I must just be lucky.

Quote from KnoxRents

4. what's the right lift height for 35's on a JK Unlimited Rubicon?
Once again, not 100% sure but I've read 2.5" to 3" is good for 35's.

Teraflex 2.5" budget boost. Installed one with another set of hands and it went smoothly (although i slightly remember the directions kinda sucking).

Heres some logic behind any BB over springs in the JK. WAY to many variables with different spring rate..2dr-4dr, softtop-hardtop, x-rubicon...ect. I was told on the phone by some company that there were 34 different spring combination dependent upon model and options, How true is this, not sure, but it does seem to make sense.

-Brad

Quote from 04TJguy

Thanks for the feedback guys. Never really been a fan of the budget boosts though I know it's an easier route. I'm hoping OME or BDS make a kit in the 3-4" range that will work....................3.8 is my only concern. Had the 4.0 TJ with 35's and 4:56's and it was ok but not strong by any means. When the hell are they just going to offer a hemi in the damn thing! I don't have the $10K or the knowledge to do it myself.

The 2010 model year seemed to get absolutely no changes due to Chrysler cutting Wrangler R & D before the sale. (Not that they'd change the engine anyway.)
It would be cool if they threw the Pentastar V6 in it but it looks like 2011 is sticking with the 3.8. No Pentastar until 2012 or 2013.

You would have to be a fool to pay 10k for some stupid hemi conversion. Ls1's can be had for like 3k if you look in the right places.