The jeep has been at the shop over a month now (long long story). They rechecked the cooling system, changed the water pump twice, and the same symptoms were still showing up. Keep in mind this is after it's dropped 40 degrees in Nashville! So they decided to pull the head on the brand new rebuilt motor to see if they could notice anything.
Upon pulling the head they mentioned that things looked "off". Apparently it wasn't machined properly. I'm guessing that's what is causing my problems. So now they have go back to the engine rebuild shop and either get them to fix it or hopefully, get me a new motor. One problem, they don't have anymore 258s. I bought the last one. This seems never-ending, and I'm positive i won't have it back for another month or so.
I'll never buy another motor from Grooms rebuilt motors that's for sure.
Unfortunately, my shop hasn't been motivated to work on it either as they won't be making a penny off this and will probably lose money.
I'm done venting, but it's looking it is was the head in a brand new motor
I thought I'd owed the board a final update after everyone's help!