help with this POS

[jimmmie '79 Cheyenne]

Got my temp guage working and noticed it's running hot now (little over 1/2 on the guage). It's also puke'n water out the filler with the cap off. It's got a new radiator, w pump, and t-stat (all less than 2 years). I removed the t-stat and the water flows as it should and the temp guage shows about a 1/4. Put back in a new t-stat, (180) after testing it to be sure it was good, and it started puke'n again. I don't think it would be the heads / gaskets or it would be puke'n with the t-stat out. I've read about burping the radiator. Think this is it ??? or is there something else my fried mind is missing. Yea, I am putting the t-stat right - that crossed my mind to. Oh...my ride is not really a pos, if it was I would not have kept it for 27 years...5 years longer than my 1st wife. One or the other had to go...know what I mean?