I have 2005 f250s on the same boat. Aprox 1100 hrs on both. No issues scoped every year by my yamaha mech. Not to say there can't be damage from corrosion in the block, but not going to remove the head obviously. To my understanding some had it and some didn't. From all I've read, usually the problem will present itself within the first 800hrs or so and as early as 200hrs. I'm crossing my fingers and assuming I have one of the good ones.
The bigger concern I would have with these motors is the lack of use and age. It's better to have 2000 hrs and properly maintained over the years as anything bad would've reared its ugly head by now. But motors that old just sitting around is not usually good.
I would try to get the story behind this, and maybe service records.
