Windshield swap?

396 Signet is right. The '63-'66 A-body windshield is very different from both of the '67-'76 windshields. This is a collossally dumb idea even if you could manage to bung the wrong windshield in; the windshield is a critical safety item. Make it wrong and very bad, very dangerous things can happen (puddles of blood, severed body parts, twisted metal, etc). And the right windshield is available for the '63-'66 cars, so…use it!