Using the Kb Calculator:
Entered these specs:
Cylinder Head 79cc
Piston Head 20cc
Gasket thickness 0.040"
Gasket bore 4.5"
Bore 4.35"
Deck 0"
stroke 3.75"
--Calculated compression ratio = 9.349:1
Rod length 6.768" (440 length)
Intake Closing point @ 0.050 = 41 + 15 per calculator instruction = 56 degrees after BDC.
Dynamic = 7.911.
That should be a cranking pressure of about 156 psi?

The advertised duration numbers look large for that cam? I'm guessing they were measured at 0.002" lobe lift? I think the true intake closing point may be more than the 56 degrees so the DCR and cranking pressure may be lower than the calculated value?