I didn't have 99'-04', I love Jeep GC.
98' is a 5.9L, 05' is a HEMI.
Change a K&N air filter, it helps, no need to change the whole intake.
enjoy, a lot of fun!
Here is the Jeep GC sweet home:
www.WKJeeps.com and www.WJJeeps.com
Here is the place has all kinds of chrome, if you like it:
http://www.truckstuffusa.com/jeepgrandcherokeechromebyputco.html