1. You leave the stop bumpstop where its at and drill a hole in the spring perch.
2. Adding a locker will not give more power. You would need to add 4:10 gears front and rear to gain the torque back that you lost with the bigger tires. You can get the rear gears from many places.. The Chrysler 8.25 is a common axle. You can get the front from a 4banger liberty or from the dealer($$$).
I have the Power-Trax No-Slip and its 'ok'.. The road manners seem to be going down hill. Its getting to where it doesnt like to lock up when offroad also.
3. Cold Air Intakes do not seem to be worth it since the stock intake is so good on the libertys. More so since you have an 04, you dont have the silencer box on-top of the throttle body. A tube that is metal will not perform as good as a tube that is plastic. Metal conducts better and the heat from the engine will heat the air in the intake up.
So no, 'I' do not believe its worth it.
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LOST KJ'S
Where are you going???
Current Jeep: 2004 Jeep Liberty
-Atlantic Blue
-Air Ride Rear Suspension ; OME/Rustys Lift ; Powertrax Locker ; Moog Lower Ball-Joints ; 245/70/16 Yokohama Geolander A/T-S's on MOABS ; Flowmaster 50 SUV
Lost #007082
http://www.cardomain.com/id/jeepjeepster