Idling issues when warm

[mikeljAAR]

My '70 AAR 'Cuda runs great but when it warms up, it won't idle without stalling when it is in gear.  I shift it to neutral (it's an automatic), when I come to stop signs, etc. so it won't stall.  The idle in neutral is above 1200 rpm, but when I put it in gear it slows down and stops.  Anybody know what the problem is here?  Thanks.

[Chryco Psycho]

what kind of carb ?DUH 6 pack I assume 
 do you have a vacuum leak into the brake booster ?
 What Cam , do you know what vacuum the engine makes at idle both in gear & out ?

[MEK-Dangerfield]

...A vacuum leak is my first thought. In my case it was beteen the carb and intake manifold.

[mikeljAAR]

Yes, it is a stock Holley 6 pack setup.  I have a Crane cam that is higher lift and longer duration than the stock T/A engine cam, engine is stock 340 T/A otherwise.  I will investigate the brake booster, no leaks under carb that I can see of hear.  It is 15" in park or neutral, and only 12" in gear with power brakes applied.  Thanks.

[Chryco Psycho]

with lower vacuum engines I have often had to reestrict the idle bleed holes , the small brass inserts inside the throat of the carb , make a U shaped wire & feed it down into the outer bleeds & see if it suddenly ides well , I usually leave the wire in place but pinch it behind the squirter By the way make the wire diameter approx 1/2 of  the size of the hole