In Reply to: 8n Head specs posted by IceChickenx on March 07, 2022 at 09:23:36:
I'm currently rebuilding my '51 8N engine and I'm following John Korschot's tutorials "Overhauling the Engine" in How-To's. In part 3 John does a nice job of explaining the piston to head clearance issue which might be of help.
I've also searched the web for rebuilding Ford flathead engines and found a great deal of info. One thing suggested (which I'm doing) is to replace the head bolts with threaded studs. Reason being the threads in 70+ year old blocks could be weak and not torque to proper specs. I found Dorman p/n 675-108 threaded studs on Amazon for $21.00 for a pk of 10. I had to buy 2 packs and also grade 8 - 7/16-20 nuts.
Hope this helps.