Not at all. A12 has small round ports whilst the A14, most anyway (id go as far as 90% odd in australia) have large oval ports. Larger valves and the oil gallery holes are differrnt. Plus manifold bolt spacing.

Unless you get a A12GX head. It looks very similar to a a14/a15 head.

Have a read of the tech section. It gives a complete run down in there.