Rear right spring looks to be missing a clip of some sort. I guess it would be best to just get a new set of springs and redo the entire rear?
I'm thinking of going with a 283 for the motor. From what I've found online, the bellhousing and transmission should pair up fine with it. I'm not sure what the rear end is yet, as I can't find any identification number on it. There's too much grime and mud caked on.