Hi Glenn

You might have a Mercury 2/4 setup from 1956,  I believe Merc's had WCFB's not teapots.  The '56 manifold has a bit more space between the carbs than the '57's and I do not think any '57 Merc had 2/4's because they were then racing the Lincoln 368 motor.  I don't know the casting number but you can see that the '56 rear carb sits futher back on the rear manifold runner at least if you have a '57 manifold to compare too. 

The valley cover can be modified with a 2lb persuader to allow you to use the manifold unless you are interested in a purely stock motor.  The covers are among the cheapest and most available parts for Y's so don't think you are damaging anything unique.

The manifold used on the 1957 "E" setups was ECG 9424 D.

Could you have mistaken the "D" for a "B" on the castings identification?

The Carter carbs  you have are not the factory intended original carbs for that manifold.

The longer carburator studs indicate that the intake was on a passenger car and not a Thunderbird.

A pair of thick bakeolite spacers was used under the  Holly teapot carbs on the passenger cars as heat insulators to keep the carbs from boiling the fuel out.

The thick spacers necessatated the use of the longer carb mounting studs.

T Birds had a slightly different setup.

There was a dual quad setup listed for the 57 Merc which was the same as the 57 Ford that I am referring to.

The 56 setup for Mercury that used the Carter carbs is a compleatly different critter which is altogether different from the 56 Ford dual quad setup.

Hope this helps.

Oldmics

Do you know if the spacers for the carbs (Teapots) are available?

Thanks

Jim

I"m not sure if the thicker bakeolite ones are reproduced but they are pretty easy to find on eBay.

I may even have a few if you need them.

Lemmie know.

Oldmics