Fronts are likely "inverted" in that the body of the shock is on the top compared to the shaft of the shock being on the top with the standard shocks. That means you have to buy inverted style fronts.
Rears *shouldn't* matter what the car came with. Best to look though, as who knows what these cars have been through over the decades. The giveaway up front is the roll pin above the ball joint bolt:
