It is against Federal law to reproduce, swap, or alter a VIN plate. You will need to get with your state's DMV or Highway Patrol to secure a new VIN and VIN plate. The only place I'm aware of on a 1966 Chevelle with a partial VIN is on top of the frame rail - see http://chevellestuff.net/qd/frames.htm. The partial VIN will only have the model year, assembly plant and car's sequence number such as 6A123456. You'll still need your state law enforcement to verify the VIN and get a state issued VIN.