Thanks for the comments Erik, John. Just curious, what compression are you running with your 51 extra cubes John?
My pistons were advertized with (approx) 10.32:1cr with 106.9cc head (btw: yes, they are domed). I took those figures to determine the total combustion volume and swept volume. Then it was a simple ratio to calculate the compression for my 118c heads. The approximate value was about 9.47:1 if I remember right.