i have an engine blick thats just got hone and got a new piston but on the processes off putting it back together i notice the bore have a horizontal scratch or water damage that my finger nail would get catch on it any suggestion

Take it back. If you can catch a nail, you probably need it bored which means new pistons too...

thats what im thinking but i already buy a new piston and got it balance so im hoping there are tolerance on the bore