Ok, so I finally got my car back, after having the engine replaced (used 305, couldn't find a reliable 350). The guy who installed initially said the car ran fine, which it did, but was a little sluggish. He adjusted the timing for me, so its good now. However, I noticed that when the engine is still cold, (less than 160 degrees), the car has a tendency to stall when idling. This only occurs when in drive or reverse. I haven't had the chance to run a fuel system cleaner through it, but I am hoping there is just some gunk in the system that needs to be blown out. Once the car warms up, it runs like a dream. Is this a major problem, or is it just being finicky?

 

Most likely the choke. See if it's operating right, if not adjust it. Lots of threads on checking/adjusting the choke, try a search on it and you will certainly find what you need.

 

Mine is like that when cold too, if I don't keep it revved once in a while it'll stall, like if I go inside to get something, it's always stopped when I get out.

In fact, all my cars with carbs has been like that, I though this was just some of the natural ways of a carbed engine...