I lifted this from a Y Block discussion on the FE forum.  Was I not paying attention in Y Block class?  3 S/C heads?                                                                                                                                                                                                                                                                                                                                                    

Yes, that is correct. The way Bill posted there and had previously posted about his motor, it may elude the 1957 312-270 hp 8V cyl head was a unique component, not the common ECZ-G head used across the board on 272-312 non supercharged applications. I was trying to find out if Bill had any info on a unique 270 hp cyl head.

The 57 312 8V 285 hp head may of been the ECZ-G, milled .060", along with dual valve springs and no oil seals.

Per ECZ-6090-G b/p, Volume of combustion chamber to be 66.35 - 69.35 cc with valves and spark plug in place.

In addition, there were at least three S/C cyl heads. EDB-C released for the Phase 1 application, EDB-D, and EDB-E.

Regards,
 Dennis]