Hey, I just thought of something else relative to this business about the '54/'55 EBU carburator usage.
In 1954, the 239 Y-block had an oil-bath air cleaner that was a little taller, not quite as big around and did not have any type of air dam at the top like the '55 Ford oil bath air cleaner did.
Also the '54 air cleaner was painted black and the decal had a silver background, black letteringand white accents, while the '55 air cleaner was painted Argent Silver and the decal had black lettering with red accents and a creme colored background.
The two air cleaners appeared different, not only because of the color scheme, decal, difference in height, but most prominently, the '55 air cleaner had an air dam stamped into the front top portion of the top drum.
Either air cleaner will sit perfectly upon the air horn of an EBU carburator.
I suspect, that the height of the '54 air cleaner may have been too close to the underside of the hood on a '55 car, so they created a '55 only design.
The '56 cars with ECG carbs had a larger air horn throat and yet another different air cleaner, this time instead of having the air dam stamped into the top, they simply curved and angled piece and resistance welded it on top. These too were painted silver and appeared to be the same size as the '55 air cleaner, but with a larger opening at the bottom to fit the ECG.
It was not possible to use an EBU air cleaner on a ECG or vise versa, they wouldn't fit.
Also it appears that the '54 and '55 air cleaners can handle the same amount of air volume ('55 is larger in diameter, but is shallower than the '54).
So here's the 60 million dollar question; why did Fomoco make a special air-cleaner for the '55 272 when the '54 air-cleaner certainly fits the EBU carb UNLESS EBU carbs were carried over into the '55 model year.
Suggested answers:
1) The '54 air cleaner fit the EBU, but came to close to the bottom of the hood, so they feared the intake wouldn't get enough air, so they made a shallower air-cleaner and added the air dam,
2) The '54 air-cleaner would have been great, but they just wanted to add the air dam. (I seriously doubt this one)
3) The '54 air-cleaner would have worked even without the air dam, they just wanted a new color and new decal. (I seriously doubt this one)
Just adding a little food for thought to the doubters.
