These were ported Indy EZ heads.
Who is preparing the RPM heads? Ask them.
I really don't like to guess and so try to only report on what I have actually done. As I have not tested any RPM heads under similar circumstances, I do not know their capability here. Now having been there.....I do know that super prepped RPM heads will make 787 HP on a normally aspirated, single 4-bbl 451 with 91 octane pump gas.
