Edelbrock didn't make them, they contracted them out.
The quality of the castings is excellent, quality control is "spotty".
For the 1910 carb alone, I've seen at least half a dozen different calibrations, so no consistancy there.
They also miss the target when drilling some passages, or don't drill them at all, or one side and not the other, etc.
Most often it's idle bypass air in the baseplate that is forgotten.
I've also seen several where the jets were at different depths in the castings, and we had to shim one side to get them even.
To this day I can't see where the 1910 would be "850" cfm, and is the exact same casting as any 1979 and later Chevy truck Q-jet. They just put some "tabs" on the secondary airflaps, and increased the opening angle of them slightly.......Cliff