The ECZ-H carb is a Holley model 4000 4V (Teapot) that was original equipment on a ’56 Ford & Merc with a 312 engine.  The Holley list number is 1161-1 which should be listed alongside the Ford part number on the base of the carb.

The ECJ-N carb is a Holley model 4000 4V (Teapot) that was original equipment on a ’56 Ford Thunderbird with a 312 engine.  The Holley list number is 1164.

If eventually putting these in the classifieds, be sure to state where you’re at.  Putting your general location in your signature helps in this regard.