Carb Problems, Need Help

I had a similar problem with my 340.....not wanting to run correctly when starting & after warming up.....it still was pretty much a basket case. Come to find out, the carb linkage was set to where the throttle plates were open prematurely and that caused it to run poorly. Once I got the linkage set up correctly, the car now runs like a scared rabbit!!
Don't know if this may be your situation or not but check the plates to see if they are open too far.
Greg.........mtn_jake