Asked this same question over in the MASS gun laws forum but would like to discuss New Jersey laws as well as the other AWB states. So instead of reposting, I'll just point you to the thread over there and when you get done reading it we can discuss it in this thread.
http://www.northeastshooters.com/vb...this-Pistol-Grip-replacement-be-legal-in-Mass
http://www.northeastshooters.com/vb...this-Pistol-Grip-replacement-be-legal-in-Mass