These engines are wickedly expensive. I don't need one, but I have some thoughts about when I do.
Assuming you could accomodate the motor mounts and front belt, could you just build out a Chev or Ford 5.0 to replace it?
I think the head gasket(s) blew or sleeves dropped on my 95 RRC. But I have not seen/confirmed yet.
I loaned truck to a buddy who claimed it was pushing out white smoke and overheating--generally (but not always) sign of something blown, cracked, slipped, warped... New water pump and...