1972 Duster , starting to tear into the build

Used wire brush on drill to strip underneath and then sand with heavy grit , very light surface rust , top side just sanding and I do use scotchbrite sometimes , got to finish sanding and get some epoxy primer on it ,, the challenger is a 72 but the outside is cloned to a 70 model grill an tail lights , 340 6 pack 4 spd