You can easily buy two new valves from ford and install them. If there is any damage to the valve seat you'll need them re-cut. If not, and I suspect the seats will be fine, then just spend the $30 bucks for them from Ford and have them installed. You should be good then.
Former owner of '99 CSVT - Silver #222/2760
356/334 wHP/TQ at 10psi on pump gas!
See My Mods
'05 Volvo S40 Turbo 5 AWD with 6spd, Passion Red
'06 Mazda5 Touring, 5spd,MTX, Black