The 2.5 is plenty of power for wheeling with proper gearing. Generally you should just accept that the 2.5 is not a powerhouse and never will be. Generally there are two mods that actually make a noticeable increase on the 2.5, an inertia ring, and a new throttle body.
|Inertia Ring -
|An inertia ring is a weight that bolts to your flywheel, it will motor keep momentum at low speeds. You have to remove the transmission to install this, so its not necessarily the easiest of mods, but the results are well worth it.
|4.0 Throttle Body Swap -
|As long as your throttle body has a 4-bolt pattern on the intake, you can bolt on a 4.0 throttle body onto your 2.5. If you have the older TBI 2.5 with the 3-bolt pattern, this swap won't work for you. The 4.0 throttle body is much larger and thus flows more air. This is a bolt on, easy swap.
Now you can do other mods like a cold air intake, and exhaust mods, and these are worth some power, but the two listed above will give you the biggest bang for your buck.