Fuel Delivery (Pump) Question

[Zilverado]

So, I started the basic tune-up last night. Left with just putting on the new plug wires. Just one thing I was kinda curious about.

When I removed the fuel line at the carb to replace the filter (fittings were EXTREMELY tight), there was virtually no fuel in the line or the filter - - nothing spilled out as I expected. Is this normal? The filter was also quite dirty.

The main reason I am doing the tune-up is the extreme rough running of the engine which just started recently, and came on quite suddenly. The engine lopes and sputters badly at idle - almost feels like a "low fuel" situation. So when I saw the "dry" filter condition, I thought could my fuel pump be going out as well?

I have had suggestions that my fuel mix is too rich, which could very well be, and I'll be looking into this as well, but I'm just trying to cover all the potential bases.

I'll finish the wire installation (hopefully tonight) and see how she runs, but I thought I'd get a jump on asking this question.