The Dart tips are much longer with the hanger arm located in the barrel of the tip. The 'cuda tip has the hanger located in the squared off end of the tip. Don't think you can swap them.
I bought a pair of the Dart tips back in the day when I didn't know there was a diff. When I changed my 'cuda back to the original single exhaust I kept the nos Dart tips and sold them on feebay. Got $250 including the nos hangers. They cost me $19.99 each back then.
