Tuning After Holley 1940 Carb Rebuild

I just rebuilt my Holley 1940 1 barrel carb for my 69 200 with a C4 tranny.
I replaced the float as well.
After I reset everything to specs, I checked my timing and it was set at 14 degrees, so I turned it back to the stock 6 degrees according to my 69 shop manual. I set the idle mixture screw to according to the Holley Tech manual. I set the curb idle at 550 and the fast idle at 1500 with my tach, and set the auto choke to the neutral position (never gets that cold here anyway).
So when I drove it yesterday, it was fine in neutral and park. But it would stall in gear if the brakes were applied, so I drove home accross the Bay Bridge in stop and go traffic with one foot on the gas and one on the brake even while stopped - only stalled 3 times.
Today I reset the curb idle screw a bit faster to prevent stalling while in gear (didn't set up the tach).
Am I missing something? I am wondering if the advanced timing was somehow helping me.
Any and all comments appreciated!
Marc in SF
63 Comet Custom Convertible
200 ci 69 six/C4 Tranny
http://mercurycomet.net

These engines typically run best advanced about twice the stock specs. So if the shop manual says 6 degrees BDC, experience shows it will run best around 12 degrees BDC if it doesn't ping.

Thanks Scott.
I reset the timing to 12 degrees and increased the curb idle a little and it runs much better. If it doesn't stall over the next few days, then I may try reducing the curb idle screw 1/4 turn every week until my car stalls a bit, then go up 1/4 turn from there. And I'l put the tachometer in the basement.
Marc in SF
63 Comet Convertible
69 200 six/Holley 1940 Carb/C4 Tranny

Hi Marc,

550 rpm at idle actually sounds a little low. It sounds OK for the car in drive, but not in park. I want to say that 700 RPM in park is more the norm. Just my opinion. Do a little experiment, if your friends, family have a tach in their newer cars ask them what the idle RPM is when the car is in drive at the many stop signs that cover SF.

tanx,
Mugsy

You're right - I reread the manual and 550 is the RPM at curb idle in Drive. I assumed it was 550 in Park since I was doing all the work alone without another person to step on the brake. I drove it 3 times today and it runs fine now. I may have the idle set a little fast but for now I am not stalling anymore.
I will check the idle speed with my Tach in drive when I can get a helper to sit in the car with the vehicle in drive while I adjust the curb idle screw. I'll compare this to my Passat wich has a tach on the dash.
Thanks again-
Marc in SF
63 Comet Custom Convertible
200 ci 69 six/C4 Tranny
http://mercurycomet.net