Engine running very rough

[kcsa75]

Typically the 350 in my truck runs like a sewing machine, but over the last couple of weeks, it's developed a couple of issues.

A few times times when I've been driving it'll cough or spit once or twice then be fine. This has been going on very intermittently for a couple or three of weeks. Then this week it just began running very rough, like it's not hitting on all cylinders.

The ignition module and coil in the HEI distributor were replaced back in the spring and I've check to make sure all the plug wires are connected. The Q-Jet was rebuilt in the spring as well and has performed flawlessly since.

My next thought is to check the fuel filter, but after that I'm out of ideas.

Any help would be appreciated.