Camshaft to Small???

I wonder if the part number for the pistons used is known, along with the actual deck clearance.

Unless some parts are not like what was originally described(pistons), I calculate the CR at well below 9.5:1.

Stock replacement pistons would theoretically sit down the hole .093” in an uncut block.
At .060 over, 81cc heads, composition gasket, etc...... it would be more like 8.3:1cr.

30+ years ago I reringed a few 400’s.
I used the MP 484 cam in both of them.
They ran pretty good for what they were, even though they were technically over cammed.
No power brakes, no highway gears though.