Extremely cold blooded 351C

I've owned my 71 Mach with a 351C for 10 years now.   For all that  time, I've never experienced a more cold blooded car.  When cold, it idles ok, but put it in gear and it stalls (same thing coming to a stop at a corner).  I have to be quick on the throttle to get it going - kinda hard on the tranny.  Once it thoroughly warms up, it's fine.

The motor was rebuilt with a more aggressive Comp cam, better pistons, and the compression raised by 1.1 points by shaving the heads and deck.  I'm running an Edelbrock Performer intake and a Holley 80457 carb.  I have timing set at 8 BTDC due to the altitude I live at, and have fine tuned the mixture by vacuum to 12 inches, which i think is  appropriate for the cam profile.  I'm pulling power for the choke from the stator terminal on the alternator,  and the choke pulls off properly.  The idle speed is spot on at 600.  Pertronix II electronic ignition and standard oe dizzy.

Personally, I suspect the carb is the problem.  It's a factory refurb I bought from Holley.  I'm open to all suggestions.

Just from my recent experience. I had the same issue. My carb was running too lean. Have you run it a good run and pulled the plugs to check them? Mine was doing the same thing. I ran it good and they were Snow White. I am running a 750 DP with 4 corner idle. I backed my idle mixture screws out an additional 1/4 turn each and I did loose a little vac at idle. From just over 12 to just a hair under 12 but the issue is gone and my plugs look nice and tan throughout.

first thing first. Check for vacuum leaks.

Same problem here. Raising idle speed helped.

They are cold running engines. My mechanic said he had to put a piece of cardboard in front of the radiator when driving

during the winter months just to keep the block warm.

mike

I recently increased my idle a bit to overcome the same problem

600 is too low for an aggressive cam. What is the idle speed when the choke has it on fast idle? I would also tighten up the choke some, so it doesn't open as fast, and check to make sure the choke pull-off is at, or even a little less than specs. You need to try to keep it a little richer while it's cold.

Everything that Don said plus more initial timing. 8 degrees of initial is not enough for any type of performance cam. 600 rpm idle is for a completely stock engine.

Get the timing sorted first.

Do you know the cam specs?

It's a Comp Xtreme Energy XE256H cam. The specs are at:

http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=846&sb=2

As for adjusting the timing up, is 10 degrees good or would you recommend more?

They are cold running engines.  My mechanic said he had to put a piece of cardboard in front of the radiator when driving during the winter months just to keep the block warm.

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Yup.  Where I come from (northern Montana, where -35 isn't unusual in the winter), they're called a "Montana Thermostat"...