OK well for break-in,
As soon as it fires up,
I immediately crank the idle speed up to over 2000. I just use the fast-idle step on the choke.
Immediately after that;
I just crank the Distributor over, without regard to any numbers, and give her as much advance as she wants, which I can tell by the increasing rpm. Once more advance does not produce more rpm, I take out a whisker, and stabilize the idle speed around 2500, using the curb-idle screw. As time progresses, I will reduce that to ~2200, cuz I'm not fond of 2500, which irks me.
After the Cam break-in is done, you can check the actual advance by timing light. Don't be surprised to see numbers nearing 50 degrees at 2500; that is normal.
When you idle her down, you can set it to anything you want, cuz at idle it's always gonna be retarded; well unless you have a very high stall.
As for me, I have a manual trans, a 230/110 cam, and a HV oil-pump, and so, I'm kindof partial to 5 degrees at 550 rpm, so I can idle around at 4mph. But for most of the time she is in the window of 12>14 at 750/800.
As for YOUR idle timing and Idle speed; you can set it anywhere you want, that's a personal preference. There are only two rules;
1) do not close the throttle so far that you get a tip-in hesitation, nor
2) so far open that it bangs the trans on the N>in gear shift.
3) Timing will be used to find this happy place. Don't be surprised to find that your Idle-timing falls into a big window from 8>18 degrees. Don't let anyone bully you into a number that your combo does not ask for. If your low-rpm power falls into "turd" category, at say 12*, with an automatic , well then something is off in your combo. Yes you can, add timing, and that will pick up the LOW-rpm power a tad, , but that's a band-aid for one of the following;
1) insufficient cylinder pressure, or
2) insufficient stall-rpm, or
3) a lousy distributor curve, or
4) a lack of torque-multiplication; ie, you need a lower first gear in the trans, or a bigger number gear in the rear-end, or, put the car on a weight-loss diet.
But I repeat;
If you run a lot of timing, then
to get the Idle rpm down, you will have to close the throttle, which when carried to the extreme will shut down your transfer slots. Yes, you can make it idle like that, but as soon as you put a load on the engine and try to drive away, Either the engine will stall, or it will stumble and almost stall. You may be able to cover this hole with accelerator pump-shot, which in this case, is another band-aid.
Oh and;
Leave the doggone vacuum gauge in the toolbox. it is a diagnostic tool, and is NOT an idle set-up tool, for anything but a factory-318 with a stock cam that idles at or near peak vacuum.
