I think it will take a bit more WOT spark than that, like 25.
That may be too much cam, or at least too much OL.
Needless to say: start rich. Stoichiometric, 14.7, 13.5 etc. are not relevant, you have to run as dark as you need to, I would begin at 12:1 or richer. In general, the same degree of anti-knock can be achieved by mix or spark, but retard kills more power.
160 thermo.