1968 350 With Edelbrock Carb and Intake Dies Out...

[Loose Screw]

Starts Up nice runs good, but after about 5-10 minutes of driving slow or at idle it starts dying out. this happens warmed up and at about anything around 1.3K rpm or below. If I pick up the rpm to 2-3K it will run good up in higher rpms, but it will start running bad again and die out if I let the rpms go down.
There's lots of gas in the glass filter at the carb and it doesn't blow smoke and I run hot plugs 26s.
I *think the plugs are loading up (I need to read them!)...also some guy told me I need some sort of carb work...I hope it's not that, heck, I Really hope it's not valves or ring work.....

Whatcha Yuh All Think.....Thanks!