@rich weyand,
In addition to how I have my dist. set as I talked about above, I failed to mention the next thing I go to is to set my carb. idle jets, according to where the rpm is after the timing is set. I have gauges installed my engine block just for timing. I have a small tach over on the inner wheel well so I know what the engine is doing. Then on a bracket installed on the front of the engine I have a vacuum gauge, and a front oil pressure gauge. The vacuum gauge is used so I can start turning the idle jets setting them for max intake vacuum on each side of the carb. I can tell what is going on after I have the timing light looking down at the harmonizing wheel when I'm at max advance as to what the springs are doing all the way to 3,000 rpm. I can do ignition and carb. settings on the side of the road. I hardly ever have to change the idle screw. Usually setting the idle jets does all I need to do with no waste of fuel.
I don't know why my engine won't run as well as it runs now with a vacuum advance on it, but I took that thing off long ago and haven't looked back. Here recently I took the cap off to change it, I could tell it needed it, and also changed out the springs for new ones to renew anything there.
And also let me mention this, the weight of the counter weights makes a big difference when you are using the springs and weights for all the advance you are going to have. The counter weights come in grams. Some allow the "all in" to come in to fast no mater what stiffness spring you've got on there. I know I've tried them all. And everyone makes them, Moroso, Mr. Gasket, Accel, MSD, Mallory I think, etc., etc. I'm using the set I got with my MSD distributor, I don't remember what they weigh but I know they are a lot heavier than the Mr. Gasket's. The counter weights are matched with the springs that come with them. Each mauf. thinks they know what works with their counter weights. I know because I've mixed them up before to see what would happen, you are better off staying with the one's that come with the counter weights. I have papers and charts for particular cam, engine hp/torq cylinder bore, rod length (piston speed), etc. to get everything set like it should be. Although it still needs a bit of tweaking and just a tad of best guess to get it just right. It's fun, interesting, and a challenge to do this and have what you've done work.