It's just a starting point and since the Eddy is a universal carb, its very possible the trim on your engine will be something other than 1 1/2 turns.

The Edlebrock circuits are very similar to the Carters. That's why I suggested the Chrysler Master Tech stuff. In fact the basic concepts are really similar to the Holley, Motorcrafts, Webber etc; they really only differ a little in how they carry out.

Don (FBO) has his own ideas on ignition curves. Since you got it, try to work with it. I like to know what is going on. If you do too, then measure out the timing advance at rpms until it stops. Then measure the vacuum advance using a mityvac.

My guess from looking at the late '60s factory curves is that 16* is plenty for a stock 440 at idle. But you could experiment.
But what is idle rpm? 600? 800?
Here's the thing, if the idle rpm is a bit high then its possible the throttle blades are open more than ideal. That would mean more fuel from the transfer ports = another possible explanation for the engine only needing a little bit of fuel from the idle ports at idle.