Thinking about pulling head on 420a again should i?

[TypeONegative]

Ok so back in February of 2016 I sold my 1999 nt I bought it back in April 2016, the guys girlfriend overheated it and blew the head gasket, I took the head off and replaced the head gasket, I saw part of the gasket was rusted through so I didn' have the head checked, so after puttng it togather the car was taking obviously water badly on cylinder 3, I pulled it again checked the head with a feeler gauge and a straight edge, on cylinder three you could stack two pennies under the straight edge, I stapled 60 grit sandpaper to a wide piece of wood and did a diy head mill, car runs perfect but when I turn the key off then back into the on position the temp gauge will within two minutes creep to the red zone, is this probably because exhaust gasses are entering the coolant? I found some oil in the coolant a while back so I pulled the far right top head bolt threw on two washers and changed the antifreeze, ever since I'm not seeing any new oil entering, do you think I should pull the head and put the rebuilt one I have on? Or might it be OK?

 

[chrysler kid]

The symptoms aren't severe enough to recommend that yet.

Perform a block dye test to check for coolant and oil mixing, perform a compression test.

That head sounds like trash, the next time you pull it off it should go in the dumpster. It is most likely past its minimum thickness tolerance. So unless you have a brand new head from the machine shop sitting next to you right now i would just perform basic tests to determine its health for now