From a friend of a friend I was told that gearing was the best way to go. I was also told that putting an air intake and headers I would loose toque. So my question is witch is the best economical way to get more power out of my jeep. I do use this to get to work and back and I need to be able to keep up on the freeway .
What are the gear ratios that I should be looking at? Or will an air intake and upgraded exhaust help just as much on the freeway? Sorry for the newbi sounding questions but I couldn't find anything in the FAQ.
First things first; yes, regearing will probably have the greatest effects (short of an engine swap!), but it will also put the biggest dent in your pocket. Gears will typically depend on your tire size and if you are planning to change axles or not... I currently run 31s with the original 4.10 gears, but I plan to switch to 33s and 4.88 (that's as high as you can go on the D30 and D35). If you switch to D44, for example, you can go higher (lower, really), and so forth. 4.88 and 33s will be about the same as the stock setup. Your own set up will depend on what you want to do (rocks, mud, daily driver, etc), the size of tire you are planning one running (31, 32, 33, 35 etc) and the axles you got on or are planning to put on the Jeep. I should point out that your rear D35 will most likely not be able to handle 35" tires, so gearing is not the only reason people change the axles... It is also done to fix the weak link on the Jeep.
Now, about the other options you mentioned... I dont have headers, but I have heard that they will sacrifice low end torque for high end horsepower.But I have not heard anything wrong about the cold air intake (quite the oppossite, actually).
Other things that can be done include an eFan conversion, improved ignition system, hi-flow cat, and cat back system to reduce the restrictions in the exhaust. You can also use a K&N filter or similar for better airflow to the engine (I recommend a CAi system as a better option), but keep in mind that the more air the filter lets by, the bigger the particles that get by as well (generally speaking), so paper filament is still a good choice for offroading.
Now, if you want to spend more than a few bucks and/or like doing heavy mechanical stuff, you could opt for a turbo setup (ther are a couple of threads here on that), or you could modify your engine (I remember YJMechanic did something like this some time back).
Felipe