Unusual RPM situation

[Figuarus]

Hey guys.

Have a problem with my 96 C1500 with 4.3L 5 spd MT

Some background.

I bought this truck a year ago, and it has been a pretty good reliable truck but since the day I bought it, (used with 185k miles) I noticed that the rpms will not drop to idle unless the truck is stopped, or under 2 to 3 mph. If im decelerating, they stay around 1300 to 1600 even when the clutch is in and the shifter in neutral. Does this when cold or hot.

Just drove it to california and back to salt lake and still did it after hours of driving. (developed a bit of an electrical issue too, but that's a problem for a different post)

Ive cleaned the throttle body, checked for vacuum leaks, and checked the accel cables (pedal and cruise control)

Im at a little bit of a loss as to what to check from here on out...

Any suggestions?