98 to 99 4.0 changes?

Hey folks, Ive found a absoloutely cherry 98 XJ. Thing I dont understand is Ive looked at several 98`s and the valve cover is the finned cast type one same as my 95`s. This 98`s is different and if I recall it was stamped steel. Is this really a 99 production model sold in 98. Im wanting to avoid the 0331 head castings but didnt check it for that yet. Any help would be greatly appricated.
Thanks.

I have a 98 ZJ and TJ, both 4.0 and they both have the exact same stamped valve cover as my '01 XJ.

The biggest change in '99 was the much larger intake manifold. Check out http://go.jeep-xj.info/HowtoIntakeManifold1.htm for pics and more info.