I have a 0331 head that was pulled from an 04 WJ. I am confused because all the searching I've done said the 0331 was redesigned sometime in 02 and should have the TUPY stamp under the oil fill cap. This head does not have the TUPY markings. Was a good 0331 ever cast without the markings? Does this mean the head is one of the heads prone to cracking? Possibly already replaced? Any way to identify the maker of the head if it isn't OEM? There was a pretty comprehensive thread on jeep strokers? I think was the website at least. That thread didn't really get me anywhere and almost made me more confused as to what I have. Just looking for any help or a point in the right direction. Thanks.