This reaching back stuff is getting tough (for me).
I'm thinking that Lou is right. Dennis' input is swaying me, too. I'm thinking that the '54 Ford and Merc heads and intakes WERE unique with their porting.
Didn't Edelbrock list different intake manifolds for the '54, '55 - '56, and then the '57 up series of y-block engines?
My first engine 'modification' was putting a '54 Merc 256 intake and carb on a '54 Ford 239. After that I swapped '55 Ford 272 dual exhaust manifolds onto the same engine. Fun!
NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York