I still think you have carb trouble....

When you turn the idle screws all the way in it should die...

Check your plugs...what color are they...black? sounds like it's flooding a little ....Improper float setting? too much fuel pressure...

Look down the carb while it's running do you see it dripping or puddle-ing fuel on the plates?

To correctly set the idle-mixture screws... set the idle around 600 rpm and hook a vaccum guage to the carb on a full time vacuum port ( on a Q-jet I use the front choke pull-off port)

Then you adjust each screw ( one at a time) until you recieve the HIGHEST vacuum reading on the gauge.... after you do this NEVER TOUCH THEM AGAIN!

First thing people do when trying to cure a carb problem is mess with the bleed screws and sometimes create more problems....