Without knowing just what you want to finish with after the conversion, advice here can be skimpy. I assume you want to stick with 6 lug to match the front. But why swap rears unless it's to run above 50mph. If you ever plan on disc on front I would go with the Camaro as Dave suggested and a late clip or MII on front with 5 lugs. That conversion would allow you disc brakes on all four wheels.
