Dart Custom question

The 69 came with a V8 no A/C. The car had 13 inch tires and wheels which i replaced with 14inch and dog dish hubcaps. I have the build sheet and the fender tag. I havent had the opportunity to decode either of them. No clue what rear end it has. I would assume its probably not the Sure Grip.
I use it as my daily driver in the summer. During the disassemly for the paint job every single bolt and screw came out like they were put there yesterday. First time ive ever had a completely rust free car. It originally came from the high plains area of Oregon.