I have noticed that the bottom surface of the factory dual quad manifolds sometimes has two large set screw type bolts while some manifolds have a completely smooth bottom surface. What is the significance of these differences? Pictured below is a two-bolt type.

 

Steve

Steve.  Thanks for the clarification on the plugs on that other manifold.  Sounds like you have two intakes?  If so, what are the dates on each of them?

 

Thanks to the information provided by Dennis K., it’s known that the ECG-D manifolds were cast at Schmeller Aluminum Foundry in Cleveland.  And it looks like there were around 5500 of these intakes cast.

 

This lead in brings up another topic which would be to identify the various casting dates for some of these manifolds.  Most of the ECG-D dual quad manifolds have the date on the top side behind the thermostat.  It would be interesting if everyone that has one or more of these intakes post their intake casting dates just to get an idea of the frequency that these intakes were being cast.

 

Here are some dates for ECG-D 2X4 manifolds to get this started:

12-14

1-22

3-29

6-5-57

Lorena, Texas (South of Waco)

Mine is 1-22 with the "S" on the bottom.

My 8V intake has a cast in 1-9 date code on top near the thermostat port, two diagonal threaded core plugs, and a stamped "S" below the cast in "ECG9424-D"  part number on the bottom side.

Another comment is the ratio of 8V intake manifolds one sees, compared to the correct 8V carbs and/or linkage sets.

Regards,

Dennis