Idle/Above Idle shake

[TheMrFlippers]

Truck is a 1995 5.0 NV3500. It shakes from about 750-1100rpm, also has noticeable vibration above 3k rpms. Truck also runs noticeably rich (black smoke when free revving.)

Throttle body has been rebuilt (just put in a 14psi spring and pod spacer today)
Injector spray pattern looks perfect.
CTS was replaced about 3 months ago (didn’t change anything when replaced)
ICM, rotor and plugs were done a few weeks ago as preventative maintenance, wires are good.
Replaced negative battery cable due to having a poor connection.
Tested TPS, tested good with an OhM meter.
Cleaned IACV
Checked timing as well (completely warmed up with wire unplugged behind glovebox.)

Only thing I haven’t done would be the distributor sensor.

Any similar issues or ideas are welcome.

Thanks in advance.

 

[TheMrFlippers]

Forgot to note that the fuel pressure was tested a few months ago, wouldn’t go above 9psi, so the pump assembly was replaced.

 

[Kobo_Dyger]

I had a 95 350 that nocked at idle, ended up being the lifters.