I went to the machine shop with a '54 235 head so that the height of that head could be compared to the height of the head in question.
My '56 848 head measured .050" less than than the '54 head. We don't know if the '54 head has ever been shaved, so that .050" difference may indeed be more than .050".
This has lead to an elevated compression ratio on a head which is already the highest compression ratio head available. Add to this, the lack of compression chamber volume near the intake valve, things are going to get hot and valves are going to cook.
Jethro from Virginia has graciously offered me a 848 head from his inventory.
I have dropped off the '54 213 head at the machine shop to be built, but I may take up Jethro's generous offer on his 848 head.
