OK I took the carb off and set the primary throttle blades so that the idle transfer slots were "square". I also took the #72 jets out and put in some #68s. I put the carb back on and set the initial timing to 16 degrees.

What is the factory setting for mechanical advance on a MSD Pro billet distributor? I thought it was 21, but to my light it looks like 19.

I still have 12" of vacuum when idling at 700-800RPM, but I have 15" at 1000RPM. The idle mixture screws do work now, but still aren't very sensitive. One thing I noticed with the carb off was that the idle transfer slots were full of carbon. I cleaned them out good and they are extremely rough along the edges. Are all factory Holley carbs like this(sorry this is my first Holley)?

I also noticed something that could be a crack going from the idle tranfer slot down to the bottom of the baseplate. I couldn't tell if it was a crack or not, but I could feel a small ridge. If it is indeed a crack this would cause all sorts of tuning problems right?

How do I put a throttle return spring on the secondary blades after I used the secondary idle speed adjustment screw? My dual return spring doesn't always return the throttle now with the new adjustments. The secondaries want to stay open a bit and then it idles at like 1800 until I lift the pedal with my foot.

Thanks for all the help...