The K&N setup, no matter how much money you dump into it will never match the Ranger's FACTORY cold air system. If you take a close peek at your grille, right next to the passenger's headlight, you will notice a ram scoop up behind there. That is your intake ducting, drawing cold air in from outside the engine bay, and sending it up to a proper filter.
The K&N system at best, with all the insulator boxes and seals and everything will still be drawing its air from INSIDE the engine bay. It can never be as cold as the factory system gets it.
Also, somewhere around here, although I can't find the thread or remember the guys SN, is a thread with the dyno sheet to prove that a K&N setup alone (IE without the hundreds of dollars in exhaust, port and polish, and tuners) will actually decrease your available power.
If you want to actually try to build some power out of your 2.9, go get a custom cam, a MAF and MAF computer, a 5.0 TB, and start building.
If you want to try and build something out of your 2.9, go start a go-cart project.
If you want to do something sensible with your time and money, like AllanD said, 4.0 time.
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