how do you tell the differance and what does a set of used 914 2.0L heads run ... for possible core for a raby / mc mark 2056

Simple way to tell the 914 2.0 head is the three bolt intake runner. All others use a four bolt pattern.

914 2.0L head cores run about $400 a set or if you have the cash for new....$1400 a head without valves at PP.