67-76 floor into a 65...

Massage to fit. That's a good phrase to use. The 67 and newer cars are wider so there will be some trimming and fitting involved to make them work. They make pans for the 63-66 cars. 1962-1966 DODGE & PLYMOUTH A-BODY COMPLETE FLOOR PAN KIT-4 PIECES

Yup, I've seen those and they aren't the whole pan..they require things like the center tunnel etc.