A 1980 vintage 727 would have come with a 3 wire neutral safety switch. The middle pin on the switch is for the neutral safety feature. the outer two pins are for your backup lights. Not knowing what modification have already been made, and how your car is wired at this point, you may have to do some wiring changes to get both of those features to work. If you're not concerned about appearance, you can do something as simple as removing the shift lever and cutting off the lower linkage lever in the engine compartment, to disassembling the column and changing over the auto/column parts, to floor shift parts (ie. shift collar, inner shift tube). I'm not sure what you need to do to go from Chrysler P/S to Borgeson P/S. Maybe nothing, maybe coupler, maybe you need to cut/weld the center shaft. Check with them on that.
