Hi Basil these things re sent to try us, I may have the same issue with my engine but mine uses cap heads not studs so maybe not as easy to fix as yours.Lets try this. I sealed the head studs with wellseal which was fine when the engine was cold but as the water temperature increased water started coming up the studs. I don't want to epoxy them in so I am trying high temp silicone and spaced the head up with wood shims and slightly preloaded the studs to take up any play. I also have a plan to join the 2 castings of the head with epoxy and make as one.
Thank you for the kind words. It's been a fun project and I'm sure it wont be the last.
Hope you get it fixed ok