I have a 2002 F250 with a 6.8L V10.   The engine was completely rebuilt less than a month ago, everything runs great, its very quiet. It had a little vibration during early acceleration, but not very noticeable, but now it vibrates during idle and inbetween 45-50 mph, but is fine any other time. Could it be a vacuum leak? Or am I looking at replacing the injectors/coil packs/ etc?

Optional Information:
2002 Ford F 250 6.8L V10

Already Tried:
swapping pcv valve, injector cleaning via gas tank, tightening engine mounts, /p>