If I remember correct, my heads had epoxy in cylinder 1,2 and 7,8, the corner cylinders. It was the push rod pinch.
My 540 made 811hp, but Kasper made 842hp with less cubes( under 500) mostly for a custom grind cam from Scott B.

I still have valves and seats, necessary for 2.25 valves change, if anyone wants a good deal. Brand new parts, heads still have 2.20 valves.