67-76 floor into a 65...

While exposed, I hope you clean rust and paint the insides of the frame rails. I did best I could using wire brushes and Rust Destroyer primer on rag on a stiff wire when I replaced the passenger floor pan and a small section of the driver's pan in my 1965 Dart. Eastwood sells a tube w/ spray head to snake inside to spray rust primer with floor pans in place (I never used). If you get inside the doors, they also need paint at the top since the factory barely sprayed upward in those.