I think this may be a choke thing but im not sure. The car fires up well, the idle goes to about 1,500 rpm when cold, the idle drops down good, but if you try and drive it before its warmed up it hesitates,bucks , and even occasionaly backfires through the carb. Once she warms up, she runs fine.
Any idea's?

 

The shop manual would probably tell you to check out the THERMAC on your air cleaner. Specifically, that your air cleaner still is still connected via flexible metal hose to the heat stove attached to your exhaust manifold, and that the hot air is being diverted to the carb during warmup. After driving for a while, the valve will permit cold air from the underhood scoop to pass through.

 

Having the same problem. Found that the vaccuum motor for that valve is stuck open (only allows cold air in). Unfortunately, I have yet to track down the part as new through ACDelco or Robert's Auto Parts. I'm on my way out right now to try to find it in a few other places.

 

The choke pull-off may be opening the choke butterfly too much at first as well.

 

How do you adjust the choke? mine overchokes when cold and loads up and shuts off if you keep your foot on it and keep it up to aout 15-1,800 rpm for about 30 sec then it runs fine all the time until the next cold morning??

 

There is an adjustment screw on the choke pull-off that sets the amount the choke butterfly is first opened. Either set that per the manual, or trial & error until it behaves properly. I did the latter.