XLT performance just north of Bay City rebuilds them. I'm sure a phone call could get you in the right direction of places on that side of the state or process to do it.
I have a cousin in Wayland that just rebuilt his 95, and i'll be rebuilding my dad's 96 XLT soon.... Once I move Pop's crap out of the way so I can use the workshop.
Any chance he wants to sell it?
Attached a quick info sheet about XLT motors....
Sounds like he didn't break it in enough or leaned out a cylinder after rebuilding it.