We've discussed Pop's Performance around here from time to time, like here:
Commissioning a Turn Key ERA 427 Cobra , so I thought I would include a link to a thread from the FE forum reporting that it has gone under.
332-428 Ford FE Engine Forum: Pop's Performance out of business ? Now I don't know whether it's true or not, but if you were thinking of doing business with them, or if they owe you some parts or work, then you might want to pursue the matter....