WJ vs JZ ?

I couldn't understand the JZ stuff on this site and I guess I discovered that the VIN on my 98 4.0 had WJ in it. Is there anything else peculiar about this model that I should be aware of? I know that I have the select trac transfer based on the owners manual.

well actually you have a ZJ, WJ (99-04 Grand Cherokee) and ZJ (93-98 Grand Cherokee). the select-trac transfer case shift bezel reads 2HI, 4HI Part Time, 4HI Full Time, Neutral, 4LO. Quadra-trac shift bezel reads 4HI full Time, Neutral, 4LO. Command-trac read 2HI, 4HI, Neutral and 4LO....

Thanks. Do you recommend the K&N and Flowmaster? Looks like I'll need a new muffler this summer!

I sure do, I have a K&N CAI on my new ZJ and I had it on my old ZJ as well along with the FLOWMASTER American Thunder System. Unfortunately Flowmaster doesn't make this sytem for the 5.9Limited, so I am going to be getting an exhaust system (w/ flowmaster muffler) from Kevinsoffroad.vom very soon...