i'm not a ford guy.  but i bought an 86 mustang for my boy when he turns 16.  has anybody  out there put an air gap on a 5.0?  is it better than spending a lot of money on the aftermarket efi setups?  if anybody could help an old gm guy out, let me know.  

If it's an '86, it should have EFI and I'd suggest keeping it.  If it has a carb, the air gap intakes work and are worth it.  They keep the intake charge cooler, whether it's GM or Ford.