I have just returned here myself after a decade or so.
When I was a young fellow a couple of years or so ago; I had a 52 Sq4.
I rode it every alternate weekend, and on the other weekends I would replace the head gasket. It would always blow at either 7 o'clock on the left rear pot or 5 o'clock on the right rear pot. Tended to toast some lower body parts.
I discovered that the steel studs expanded differently from the aluminum head and the result was that the aluminum always crowned up around the base of the stud. So file the head and block down a few thou and the new gasket would seal and run until the engine cooled down. Then after startup the next time or so, the gasket would blow again. I never thought of it before but the compression must have been increasing over time.
If you think of torquing the stud, it was a poor set up as half of them just bear on on of the fins of the block.
Since you have some experience, have you any comments. I have not yet run into another with the some problem.