Truck Norris might have a timing issue? Vaccum issue? MightyMax3.0 4x4

So basically I have replaced a large portion of this Truck last weekend.

Starter, Ignition Coil, Alternator, Master Cylinder, Fuel Filter, Distributor, Rotor.....

Mighty Max 3.0 - 4x4 - 160K

However the truck idles funny. It drives pretty great, but at low rpms it doesnt quite run right. A lot of vibration and sound.. but only 70% of the time. There is another 30% when it runs great, nice and quiet and doesnt vibrate.

I am thinking a timing issue? Or maybe the vaccum ?

When I start to give it a little gas it kicks in and runs like a champ.

Check fuel rail pressure. Sounds like it's a fuel issue. IDK what the regulator should be because it's a 3.0 FI. You will need to hit up one of the FI guys. They would know what to look for in the line of pressure and things like TPS settings and adjustments.
OR it's an EGR valve stuck open at times. When there open it will idle like crap. Just pull a vacuum on the EGR valve to test. Some valves you can reach around the back and stick your finger in the hole in the back to push it open. If it runs like crap when open and better when closed it might just be partly closing and needs to be cleaned out real good.

Who are the FI guys?

^ Fuel injection. :)

Geezer, you're back!