LS6 intake making car hesitate
moderate vacuum. Speaking of vacuum, a leak check
all around the base of the new manifold wouldn't hurt.
Lean conditions are more "jumpy" than even or rich.
High manifold vacuum (deceleration in gear) would
expose a vacuum leak the most.
Note: Don't remember if there are 1 or 2 of those plastic clips, but it needs to be removed. The clip / clips are held to the wire harness with some very tough black tape.
Ron,

