What's causing my rough idle?

[Scutty]

My 68 has it's original 40PII carbs, with recently rebushed shafts and good contact with the throat all around the butterflies when closed. I've just put in a new 055 distributor, new wires, plugs, and coil. I've got my static timing set to 5deg btdc, as most suggest for the 055.
The car won't settle in on a idle speed. In trying to sync the carbs, I set the idle to 1000 or so, and a few seconds later it's at 2000, then a few seconds later it dies out, and a blip of the linkage is needed to keep it running, then back to 2000, and so on, and so on. I can't get it to settle in allowing me to use my sync tool.
The previous owner told me he put in a real hot cam, cheap horsepower, he said. Could this be the problem? Shoud I adjust something to account for the hot cam?
I have had trouble starting the engine when warm. The car left me stranded at the grocery store, could this be related?
What experiences or ideas do you guys have?

[jac912]

Does it cut out at 2000 rpm 'cause it starves or because its choking on too much fuel? Too rich you'd see black exhaust. If neither then it's a spark problem. Hope this thinking out load helps.
Jim in Ma.

[mein12]

Hi,
Spend the money and get a timing light that will show you full advance. This will allow you to see your timing at 3000 rpm. You should read no more than 34/35 degrees for a hot street motor. With some fuels 31/33 total advance works well.
Getting back to the carbs, there are many things to look for. Split shaft carbs are particularly challenging if not set-up correctly.
Please elaborate about the components that went into your engine. This will determine jetting requirements. A little more info will go a long way in figuring out where to go from here.
Regards, JMB

[Scutty]

To answer jac's question: Nothing seems to be choking or starving. When idling, the thing simply adjusts its own idle speed, sometimes below 800rpm and it dies.
I followed mein's advice and adjusted the timing with a light. I also played for a long time with the idle mix screws. I now have the car idling decently and it seems to start well when warm (I've only tried twice). The advance reads about 10deg at idle and about 39deg at 3000rpm. Is there any danger in this much advance? It seems to idle and drive well. (Only about a 10 minute test drive)

The car is stock except for the 055, and the hot cam. All of the emissions equipment has been removed and I've plugged the two little vacuum tubes at the bottom of the carbs.
If I were able to find out what specs the hot cam had, could anyone tell me if I have the right jets and timing?
Do I need a different valve gap for a hot cam? I'm using .004 and .006, just like the book says.

[mein12]

Hi,

39 degrees is too much and will cause problems for you. Try not to exceed 36 degrees. You will have to run premium fuel, but you probably know that already.
Nearly every cam ground today uses the stock lash settings. If your car is still running stock displacement (82.5 mm bore) your jetting should be something like 180 air correction over 130 main. Your idle jets will work fine the way they are.
If it is a big bore motor 130 to 137.5 mains will work. You might need to change the idle jets as well. It depends on what year your carbs were made.
Anyway, good luck. JMB