Alloy heads corrode and nothing speeds this process up faster than using tap water in your cooling system.
A head job on a Ford is just part of life really, late EL's and AU on with the Intech engines and metal head gaskets seem to be holding out ok, but they are not that old yet so only time will tell.
If you buy the EF, just put aside about $800 for a headjob, you will need it sooner or later.
Car's I have owned. First car purchased in July 1994, in order of ownership.
VC Valiant 245Hemi, 280zx Nissan 5 speed, 88 EA 3.9CFI,94 ED Gli X Chaser, 79 FC LTD, 351, FMX, 91 EA2 Fairmont Ghia, 1999 AU S pack, 2000 AU Forte, 1992 EB2 XR8, 2001 AU2 SR, 2002 VX2 Acclaim, 2002 VX2 Manual S pack,2003 BA XR6 manual, 2001 VX2 Berlina.