750 Eddy Carb issues

Gator said
Question for anyone who can give me a good answer. I have a 750 Edelbrock on my 340 and it has been giving me problems lately where I cannot get it to idle consistantly. It sounds as if it is sucking air. Under acceleration the car runs great. Changed everything that has to do with vacuum , replaced the 2 caps on the front of the carb, new PVC, new Carb gasket, put on a new fuel regulator with 6 psi, checked the tubular fuel filter, etc.. and still will not idle consistantly. Since the carb is 14 years old and has never been rebuilt I took the carb to a very established engine builder and when he was tearing it down he noticed a few of the Metering Rods were broke. Now how do these break? The carb since I have had it has never been apart. This really confuses me...

Here's something for you to check.
At idle look down the carb two front barrels and see if fuel is dripping from the two boosters I circled in red.
If you have ANY fuel dripping from these at idle it's because there are a small brass plug with a really small hole (air bleed) in the back side of these that gets plugged up with age. (most people miss this)
When the air bleed holes in the brass plugs get plugged up the idle vacuum is enough to pull fuel through them.
The holes let enough air in that at idle they don't pull fuel.

This would severely screw with your idle mixture and make the idle need to be higher to try and compensate for the extra fuel.