poor running car

["my69300 <tubman@xxxx>" <tubman@xxxx>]

Hi everyone
It's been a while since I posted.
Here's my problem I have a 69 300 
with a 440 and a 4 barrel-- the car
is and has been running like crap.
The rpm's at idle will go so low
it will almost stall then the rpm's
will return to normal then go back down 
again. It will keep going up and down.
Once I get to the open road it runs great.
I posted this problem a month or so ago
and you guy's said maybe the problems
was the carb,but try the cheapest first.
So I did I did the plugs,wire and cap
first.That helped very little but it
did help.Next I had the carb rebuilt.
Yesterday was the first nice day in 
while so I install the carb.
The problem is still there,what am I
missing???