While I don't know very much about aftermarket heads for the 4.6L (almost nil
). I do know that the AFR heads are not going to fit on your 4.6. Nor will any 302 or 351 head. You need an OHC head. I believe ford has one, but there must be a few more choices out there by now. Pick up a MM&FF and check the ads, there has to be someone in there that is selling them.