Just plan on replacing the piston if he doesn't know if you end up buying it. Pull the top end to see what you have in there before running the engine any more. If it already has a Wiseco when you get it apart, well, at least you have the peace of mind it won't grenade on you and you know what condition the top end is in. The price of a few gaskets and a little bit of your time is better than a grenaded piston that takes out the top and bottom ends!