Two of my Daughters have '97's (... talk about lucky!) One has already dropped the #4 (approx 143k miles) I rebuilt that engine ... big mess: I'm taking the other engine (175k miles) apart before it happens. My cyl head repair outfit, Dover; swears that if they do the cyl head repair ... the valve seat will never fall afterward because they (Dover) will properly "cinch" all the valve seats ... something apparently Ford never did very well. (I can see impressions into the aluminum around the valve seats where they have done something ... hopefully it works ... time will tell.)