I am having the dealer install the class IV hitch and ball on my 07 LE. How can I tell that I have a ball and mount rated class IV and not III. I am afraid they will try and screw me. They threw in a class IV complete package in the deal when I bought the truck. They said I would be ready to tow 7400 lbs. I am a little scared because the salesmanager ordered the parts and I do not want to recieve a class III. Thanks.