Here are some pics with the body off of my 66 GMC...
pic ! behind the drivers side cab mount
http://kieth.smugmug.com/Trucks/66-G...822_WxqJJ-A-LB
between the steering box and the drivers side front crossmember:
http://kieth.smugmug.com/Trucks/66-G...18287733_RYPBg
Inside drivers side door opening top middle:
http://kieth.smugmug.com/Trucks/66-G...774_EwLZF-A-LB
Interior drivers side kick panel by air vent, gvw tag, with engine,and plant location:
http://kieth.smugmug.com/Trucks/66-G...749_AVav7-A-LB
That is all I could find on my Truck.........
Oops found another : top of frame under cab drivers side, same as the one on top of frame behind steering box. this one is in front of the center crossmember:
http://kieth.smugmug.com/Trucks/66-G...896_MLQa4-A-LB