I used the info in the screen shot, which had the chamber volume at 62cc.
Swapping that to 58cc changes the results from 9.37:1 up to 9.82:1
With 58cc heads and zero deck it’s 10.11:1.
That’s assuming the 5cc valve pocket volume can be taken at face value.
FWIW, the KB catalog shows the 318 deck height as 9.578, and the piston to end up at +.010” out of the hole.