Since the C4 the corvette has been a unidoby in some form or another. They started out as a body bonded to a frame, similar to the full size vans we're talking about, and then eventually transitioned to the standard unibody design. They make it a point of calling it a monocoque chassis though so people won't think of it the same as they do a Camry. When comparing an 80's vette to an 80's G series you have to take into account that a steel van welded to a truck frame isn't as weak as a plastic and fiberglass body glued to a lightweight sportscar frame.