Edelbrock also reproduced Quadrajets for a while and called it the QJet. You might be able to find one of those and use it.
The Edelbrock 1406 throttle bore diameters are 1-7/16" on the primaries and 1-11/16" on the secondaries. The primaries fall within the specs of the 800cfm and 850cfm ThermoQuad primaries, which were 1-3/8" and 1-1/2", respectively. The secondaries on both versions of the ThermoQuad were 2-1/4", IIRC, much bigger than the 1406.
Here's a link to Edelbrock's carbs, to help you out, Eric:
Edelbrock Performer Series Carburetor Owner's Manual
