Standard 6v stoplight bulb in the AD is a 1129 Chris, which is 21cp.
DG
Unless the truck housing is considerably different in size from the car housing the 1129 is too long to fit without bending the bracket. I believe the stock tail light was the #63 and brake the #81. Bending the bracket to allow the 1129 to fit is the modification I referred to in the link in my post above. When I pulled my '38 out of the barn and drug her home it had #63s in both sockets. Talk about dim.
