72 Dart rear help. What do I have?

Moved the 72 dart to the front of the shop. 318 car. 7 1/4 rear end. The purchase was 3 years ago and included two additional rear ends. One housing is 3723599 and is a posi the other is 2852905 and is a one legger. Are either of these worth installing? This is intended as a budget build for my wife. The 318 is done. I have two auto transmissions and ready to put the drive train together. I ordered the leaf spring relocation kit to allow for wider tires. New rear quarters are fitted but not secured. I figured I better get the rear end figured out first. I bought the car for $1000 with a ton of parts. $700 for the 318 that has been gone through and a ton of additional parts. I need some guidance on the best path forward on a rear end path. The 3723599 rear looks like It’ll need a lot to get to A body width. please just tell me what to do. I gotta get some progress on this build. The house is getting kinda cold already…lol