'66 Slant Six Turbo Build

Quick update on this ancient thread: it's been the better part of year and I finally bolted up the head gasket / fire ring solution to mixed results. The combustion chambers are sealed up and by my estimation bulletproof, I'd wager they could handle 40-50 PSI. However, the tolerances were a bit off and I'm not getting the compression I need on the gasket to seal up the water passages. Either the receiver grooves were too shallow, the rings too big or the deck is off somewhere.

So, not quite back to the drawing board but going to measure a few things. Also, going to call SCE Gaskets and see if they can drum up a recommendation for me.