Using my old flashes with Nikon D5200?

I used to shoot professionally many years ago and still have 3 "potato masher" high power flashes. Is there a module that can be purchased for these Sunpaks ( 622, 522, 555) to use them today with my Nikon D5200?

No TTL module that I know of, but you can still use them all in Auto mode. A Nikon AS-10 PC socket adapter may be required, don't remember if your camera has a PC socket, although I doubt it. Or something similar… Not necessary to use the Nikon piece.