07 Silverado - Vibration at acceleration & Deceleration
 

My old 07' new body style is still going at 190,000miles with few problems, but has developed a vibration at acceleration and deceleration. It is similar to a motor mount vibration and only occurs with slight acceleration at all speeds. If feels like it is either a transmission shifting issue or a AFM issue. It is most noticeable at lower speeds and around 1000 to 1300 RPM's, but occurs at higher speeds trying to maintain a constant speed. At 70 MPH a slight deceleration a short vibration, then when picking the throttle back up slightly, short vibration again until it picks up speed and RPM's. It's not a suspension issue, that has been checked and rechecked, new tires, new motor mounts (again). I am having electrical issue with a alternator that is giving out (reading can go from 14.5 to 12.3) and will be replacing this weekend.
My thoughts, AFM issue, fuel injectors low volume, transmission mount, transmission fluid issue causing torque converter delay, electrical problems causing the AFM issues......
Any comment would be appreciated.
Thanks!!