I have an 08 JKU Rubicon. I want to put 35's on it here is what I have been thinking.
2.5 lift w/ shocks
keeping stock rim's with wheel spacers (Will I need spacers)
Also, I shouldn't have any driveline problems should I? Thanks.

 

with wheel spacers, that'll do the trick and, so long as you run shock extensions or shocks made specifically to not exceed the additional droop you would get with 2.5" of lift, you shouldn't need a new front drive shaft.

 

2.5" with 35s will work. Your 4.10 gears will suffice for now. you may consider a re-gear in the future, but no hurry. Spacers- It depends on the width of the tire. If you go with a 35x12.50r17, then yeah you'll need a good set of spacers to fit the new meat. Although, even a skinny 35 might rub a little on full turn just cuz its a big tire.

 

right, the pinch seams will need to get trimmed a bit too

 

Even with the lift? I know I have seen threads where guys are running 35's on stock suspensions and trim the pinch seam. I wouldn't think you'd need it with the lift. I KNOW NOTHING so this is a question, not a comment.

 

nope you wont need a driveshaft, atleast i hope so because i have a 2.5" lift with 35's

 

I'm buying 305 70 17's( supposed to measure 34"s. Do I need to trim the pinch seam? This something I have not thought about. I have a RC bb 2.5 lift with shoch ext. and 17x9 xd hoss wheels with 4.56 backspacing. Is it best to trim the pinch seam or can you just bend it over?

 

I've wheeled the shit out of my set-up and have not trimmed anything. Duratracs are small 35's...

 

Best thing to do is toss on the tires and flex it some where. Just not on a trail run. This should show you what you need to do.

I have true 35's and a 2.5 coil and had to trim 1" off the rubi rock rail and I bent the pinch seam. (I was rubbing on speed bumps.) However, cutting the pinch seam is a better option as the paint chips and peals when you bend it. If you cut it (sawzall) you can then do a light sanding a little black paint to protect the body from rust.

 

Those stupid pinch seams... Has anyone tried JB weld?

What a stupid design.

I really like the thought of the 2.5" idea but has anyone had this setup and run stuff like Hells Revenge? (sorry, thats the only place i can think of that a large number of people have run).

I ran behind a JKU with 4" and 35's and he had no problems, just wondering if 2.5" is acceptable?