Motorcycle Repair: 500 nighthawk tank, honda nighthawk 650, fuel tanks

Question
will an 83 honda nighthawk 650 tank fit an 83 nighthawk 550? i only ask because the 550 tanks are really expensive and i am trying to save a few bucks on replacing the tank!  
thanks

Answer
This may work but Im not to sure of the width of the rubber mounts by the steering head. All fuel tanks are expensive no matter what make or model. Can you borrow one and put it on the bike and see if the fuel petcock will clear everything underneath and when the fuel line is on that not pinched or kinked.