I believe mine was the PerTronix Interceptor and if I remember right it came with everything needed to do the conversion. Should run you between $85-$120 depending if it's the Interceptor or Interceptor II. Not sure what the difference is. You can order one here:
http://www.skidim.com/searchprods.asp or call them and they'll be able to tell you exactly what you need. Those guys are reall good.