When I shipped my intake manifold to Ted, I shipped it by UPS Flat Rate (not USPS), using my box. Rather than having it picked up at my door, I dropped it off at the nearest UPS-authorized store. The cost to ship the manifold from Northern California to Lorena, TX was $22. I included a return shipping label but was charged an additional $9 for pickup at Ted's place. Shipping prices probably have gone up since then. The ECZ-B intake weighs approximately 31 lbs. You can ship up to 50 lbs. with UPS Flat Rate in a box that does not exceed 1728 cubic inches.

Keep the slots straight at the divider.  Joe-JDC

JDC

Thank you for the education.  I will see if I can find a local shop to mill it, shipping costs are pretty high the past few years.  Do tell them just to make the surface "flat"?

Could I use this insulator as a template to open the holes?

While the actual slotting of the holes can be performed by the do it yourselfer, machining the flange flat does require some form of milling operation.  Due to shipping costs, it’s always worthwhile looking for a local machine shop that can do this operation as shipping costs can easily outweigh the actual machining operation.  But yes, if the manifold is shipped to me, I can do that slotting operation to it.  Just email me directly regarding doing that.

Here's some more info about FYB intake manifolds in general.

Ford did an extremely good job in matching the air flow requirements of the ECZ-B intake manifold to that of the 1957 heads and camshaft.  Issues with that factory air flow in the ECZ-B manifold occurs when the camshaft is upgraded, the cubic inches are increased, the compression ratio is increased, and/or any porting in the cylinder heads takes place.  When any of this takes place, the ECZ-B manifold is then lacking in air flow to keep up with any of the aforementioned changes and then requires modifications in order to keep up with the revised flow requirements.

While talking about intake manifold air flow requirements, I have tested both the ECZ-A (Teapot) and ECZ-B manifolds in a back-to-back dyno test and the ECZ-B handily wins this contest.  In this particular test, a dead stock ECZ-B manifold is worth 27 horsepower over the ECZ-A manifold.  Both intakes were tested with a 750 cfm Holley carb.  Ledges at the carburetor flange was evident in both instances so there’s more to be had in both instances.

When I modify the ECZ-B intakes so that they are dual slotted, I typically do that so that the larger bore carburetors fit without ledges or flow restrictions at the entry point of the manifold.  If using a carburetor spacer, then the sizing of the holes within the carb spacer are taken into consideration.  For most of these modifications, I use a Moroso P/N 64930 four hole spacer as the template for hole placement and general sizing.  As Kultulz brings up, the ’55-’57 Thunderbirds are not carb spacer height friendly so take that into consideration.

In machining the Mercury 8 Restorations (M8R) aluminum 4V intake manifold entry bores from the as supplied 1.510” to the 1.783” size, there was an 8 HP increase.  Very significant increase and without making the entry slotted.  That manifold was tested in both bore size configurations with the aforementioned Moroso 1” 4 hole spacer but had a ledge or flow restriction at the carburetor flange with the 1.510” throttle bores.  The increase to 1.783” simply had the throttle bores in the intake manifold matching the carb spacer which was then topped off with a 750 cfm Holley also with 1.783” carb bores.  Here’s a picture of the M8R intake before enlarging the throttle bores.
 

Lorena, Texas (South of Waco)

THANX AGAIN (also Daniel Tinder & Hoosier) for edumecating me.
 
If no damage to the 12V points and condenser with a 6V system it is a cheap way out (1955/56).

____________________________

Not a cheap quick way on a ‘54 239. I had to change the oil pump and oil pump drive to match the distributor. My 239 also has a 312 crank in it. My best has been a 16.88 @ 82 mph.

  Dennis in Lititz PA

Ross, you might want to talk to MarkR on VTCI; he has a 55 Tbird. He recently switched from the Holley 4150 Street Avenger 570 carburetor to the Holley 4160 390 cfm carburetor. His car has a manual transmission. Having looked at photos of his car, I think he retained the original throttle linkage. I, on the other hand, converting the Fordomatic to a C4, I'm using Lokar throttle pedal and both throttle & transmission kickdown cables.  

If its was me ...  ... I would try and find the correct 1957 H4150 core and rebuild or have rebuilt the HOLLEY as the OP still has to consider the needed 1957 TV LINKAGE changeover (from 1955 H4000) if a F/M.

That and the proper phenolic spacer (OEM on 57 FORD and BIRD H4150 - B7AZ 9A589-B)

Another thing to consider, is the 1955 ACL ASSY oil bath or dry.

____________________________

While the intake is off is the time to mess with it, obviously.  I have no hood clearance concerns but am running a 1" phenolic spacer in between a 9425-B and a Holley 1850-?.  I used a die grinder to make the transition from carb to spacer and spacer to intake nice and smooth.  If hood clearance IS an issue, use your 4-hole base gasket as a pattern and open up the intake enough that it all fits, if you need to.  According to the Holley "List," the 1850s are 1 9/16" throttle bores.  They show a 450 CFM that's 1.5" (List number is R4548).

"I’ve converted my ‘54 239” to the ‘57 and up distributor, must be close to 20 years ago. I’m still 6 volt. Used the points and condenser from the ‘57 and up distributor."

... hmmpf ...

THANX for the reply.

So no point (12V) burning, pitting or condenser failure(s).  6V coil and no overheating? It keeps the plugs clean?

Cheap quick way out of the LOAD-O-MATIC.    

____________________________