When I changed a set of heads on my Challenger it took a couple of weeks for everything to show up. I put it all back together and it would not start to save its own life. After some serious head scratching I finally realized I had put in the small block electronic ignition distributor instead of the 383/400, the only difference besides the firing and rotation order was the tag was purple on one and red on another, I kicked myself for days on that one.
