AVS2 accelerator pump plunger too small

Some conclusions: 1) I didn’t notice that the pump well is tapered top to bottom so a plunger will be tighter by the time it is in the pumping position. No matter, the one supplied on the new Edelbrock AVS2 still doesn’t work. 2) As Bewy said the nominal size is 13/16, and I checked a 1969 Carter AVS which is the same. 3) The one I got from Quadrajetparts per RRR’s suggestion works fine. I checked the Edelbrock one again after sitting in fuel for a bit as suggested by their Tech. It will never work. It’s junk.