there is a kit u can use that will determine if u r getting exhaust gases in to the coolant system.
https://www.amazon.com/Lisle-7…ak-Detector/dp/B0007ZDRUI
Head gaskets r not that hard but u would want to get the head magnafuxed to check for cracks and depending on miles u may want to have the valves done.
Does Jody sell those too?
I have a head if you end up needing one. I will check the casting number on it but its fresh.