Some of the parts that come to mind are: front end (hood/fenders etc.), windshield/back glass, front/rear bumpers, front seats would need to be modified to fold forward, back seat should fit. If your going use the rear bumper you can use the mounting hardware from the '73 however most prefer the '71/'72 mounting brackets. The front bumper may swap easy. There are many small differences but everything has been either tried or done before. Do a search on what you're wanting to do and you'll likely find the answer. Where are you located?
I used 4door quarters from the middle of the wheel arch back. Backglass won't work. I keep my cut-up 4door carcas laying around for odd hardware. (Its nice to not have a home owners asociation.)
