Well I was having a pretty good day installing a new .50 over piston in the XL until.....
I obtained a new head I was going to install.
The PO left the plug in it and when I went to remove it so I could clean up the head...
After spending some time on it I don't know if it's going to come out. (At least without trashing the threads.)
I may have to use my old head after all.
*sigh*
A side note, it takes a lot heat to heat an item designed to be a heat sink!