a B18C head, in FACT, has more quenching than the B16 head, thus giving more compression ratios. i've seen some of my guys slap on the b18c head on b16 blocks when they blew thier b16 heads, and raise their compression ration by .5 to.8, the only the difference about the heads is the b16 has more of a better air flow port.
I myself have a B16A2 head on B18C block. When setting up for this application, you'll lose compression by .25 to .3, in order not to lose this CR, instead of the 3 layer OEM, use only 1 layer, and torque the heads about 10lbs more on final torque.