The ecz 9425-b intake i have came with a slightly angled composite (probably phenolic) spacer. Is this a factory spacer? If there's a factory one, what does it look like?

The 1957 312 4V engines came with either a ¼” or ½” thick 4 hole carb spacer and those could be either phenolic or aluminum. All the 312 phenolic spacers I have are ½” thick but the aluminum ones come in either thickness.  Car versus Thunderbird maybe? Those spacers were not angled and simply raised the carburetor an even amount.
 
Here’s a picture of each.
 

Lorena, Texas (South of Waco)

The '57 Ford 312 carb to intake spacers I've seen were 1/2 inch thick phenolic plastic, dark brown in color. These have had no identifying letters or numbers on them.  Also, they had no taper that I observed nor markings to indiate Front.

The '49-'59 Ford car Text Catalog lists 3 spacer part numbers for the 312 engine
B7AZ 9A589-B  -  use w/ Holley 4 bbl. carb.
B7AZ 9A589-D  -  use w/Ford and Carter 4 bbl. carb.
B7AZ 9A589-F  -  (no description of carb assignment given)

I've come across several 1/2 inch thick die cast aluminum carb to intake spacers on '58 Fords equipped with 332 and 352 engines.  Like the '57 312 Ford/Mercury phenolic spacers, these were for a small throttle bore Ford (Autolite) or Holley 4150 carbs.  The bottom side of the spacer had the casting number EDB-9603-C. 

Perhaps there is another carb to intake spacer part number for the 292 Ford big truck engines w/ 4 barrel carbs.  -I don't have the truck Text Catalog to reference.  MAYBE there was a tapered spacer used on some truck application.

Hope this helps.  


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

Following up on Ted's info.  All '57 312 'D' code (single quad, non-supercharged) Thunderbirds used the 1/2 inch phenolic plastic spacers in conjunction with the new for '57 Holley 4150 carburetor.


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

Possibly marine use? They all seemed to have tapered spacer. Not all Y's had that flat Carter YF set up.

56 Vic, B'Ville 200 MPH Club Member, So Cal.

Thanks guys, now that i think about it, yea i bet marine use. Car motors in '57 were red right? this intake was blue.

Yes, Shaggy, the three sets of 113 heads I've seen were painted blue and had been removed from marine application y-blocks.

Too, I think that DryLakesRacer is very likely to be correct.  Marine application y-blocks using a single four barrel intake manifold may very well have used an angled carburetor spacer.  That's a better bet than a heavy duty truck application that I suggested.  


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York