I think you have a very small compression leak into the cooling system. I had something similar happen in my race car. It would leak very little coolant into the cylinder but the compression and firing in the cylinder would slowly pump gasses in to the cooling system until the pressure got high enough to blow out the radiator cap. Then it would begin overheating. The problem was a very small crack in the cylinder wall.
I had a similar thing happen to my 428 CJ engine and it would have bubbles coming out of the coolant reservoir after shutting it off. The problem with it was a very small compression leak around a cylinder sleeve. I was able to seal it with an expensive block seal.
It doesn't seem likely that a bad head gasket would have this kind of symtom but it is possble. It is more likely a metal crack.
Both of those vehicles ran very well while it had these symptoms. The compression leak was small enough that the compression was not reduced much.
2002 FX4 Bright Red Supercab 4.0 SOHC, manual 5-spd & Tcase, 33" BFG MTs, K&N air filter, Modified air box inlet, Gibson SS cat. back exhaust, Bama flash, Hidden Hitch round receiver, Rear helper air springs, Electric trailer brake controller, Line-X bed liner, WAAG bar with KC lights and Wildernest shell.