Important Info: Truck just got transmission & transfer case rebuild finished a couple days ago. Truck has headers (No EGR tube for ports in block) no cat, thrush muffler, missing smog pump, and believe failing fuel pump cause of long crank time and sputters until truck runs when cold. Truck has new O2 sensor, TPS, IAC, and Fuel Pressure Regulator. Temp sensor works but temp gauge is freaking out going all over the place.

When the truck was started and moved out of garage after I finished the rebuild, and went to go test, it had high idle & was rough with it slowly reving up then quickly dropping down but later cleared up. Once truck has warmed up and is in neutral or park, it's idle sounds to be around 1500-2000rpm, which when put into a drive gear cause the truck to jerk real bad and drops to about 900rpm. The way I've been dropping idle is by putting foot under gas pedal and pull up on it. Sometimes it will idle down to about 1000rpm and shift from park to reverse without jerking. Can someone help me tune up this engine to get it to idle and run right.

 

Vacuum leak somewhere.

 

I'll double check and see if there is one, but from all the diagrams and everything I've looked at all the lines should be fine and be hooked up to the right place.