pre-cups... again

[dieseldummy]

I have spent countless hours researching all posts about precups. I have basicly got the impression that there are 4 types: C, J, T, and T cups with a diamond opening. My question is in what year were the diamond "T" cups introduced? My '93 has "T" cups, but the opening is flat on one side and rounded on the other. Any information would be appreciated.
Thanks,
Justin

[JeepSJ]

I don't think diamond has anything to do with the shape of the opening. My cups are stamped with a diamond shape, so I'm assuming that I have the diamond cups. In fact, I had Jamie at Diesel Depot send me a couple (to replace some severely cracked ones) and I told him that I had diamond cups and the ones he sent were exactly like the ones I have. I'm not sure what year they started using the diamond cups - mine is a 97.