you can get a good pair of iron gt40's, for about 500 or you can go to a junk yard and find a 99 explorer or one of those years with a 5.0 motor that came with gt40p heads, plus a gt40 intake which will bolt right onto our cars, except you need the special headers to make them fit. If you have the money buy a pair of trick flow twisted wedge heads or afr 165 heads. Which will run you about 1300 for a pair.
Even if you get a set from the junkyard, by the time you have them rebuilt you're lookin at payin 1000 dollars anyway. So you might as well snag a pair of AFR 165's. Although you can't go wrong with the TW's or Edelbrocks. Trickflow was the first one to offer a 5.0 head after all..