I have a 350 with a 4bbl quadrajet. Both are 1969 versions. Carb has divorced choke. I have adjusted this thing until I am blue in the face. Runs pretty good most of the time but sometimes when I give it hell from the stopped position it has a kind of loud single pop. Sounds like air popping. There is never any fuel on the lid of the air cleaner. The car bogs bad when it pops also. This has also happened when I am at driving speeds and floor it.
Does this mean too much fuel or too much air or something else. Just looking for someone who may have some knowledge of adjusting these things the right way.

Thanks for the help.

The popping usually means too lean, that may be the case if the engine isn't 180 degrees F or more. About all you could do is wait for the warmup, the choke will open before the engine gets warm enough usually.

After it sits overnight, open the throttle, the choke should close, you should feel a little pressure when you work the flap open and close with the throttle half open. (Gee, this is hard to communicae in typing lol) Basically the more pressure you feel, the slower it will open. The tough part is once it starts you may as well wait till the next morning...

Something else to think about is the power valve in the carb and the accelerator pump. Maybe the check for the accel pump isn't checking the fuel or the spring in the power valve could be too light or the valve stuck.

Too many variables to diagnose online hehe

Hope you get it figured out, wish I could help more.

Either bad accelorator pump or most likely the secondary air valve is too loose
that's my bet.