Another still accelerator pedal thread

[Tilt]

I picked up an 85 Sierra Classic a few months back that I've been working on. I noticed when I first got it that the gas pedal was pretty stiff, but parked it and started on the interior and general clean up. I fired it up yesterday for the first time since then and the peddle is really hard. It's stiff enough that once you get it to move, it will hold that position and not return to idle without getting out and physically doing it at the carb. I can kill the truck and everything works and feels like it should. The pedal is not hard and throttle returns with no problem. Any ideas on where to start looking. It has an Edelbrock carb with a 3/4"-1" adapter/spacer.