Take it over to the machine shop. The first thing they will do is clean it, check it for cracks, then measure the bore to see how big it is right now. The taper of the cylinder might be to great, the scratch to deep or the deck may have been cut down to far to reuse the block. It it is good on those 3 things then they look to see if pistons are available to fill the holes they are going to cut. Many times it can be less expensive to find a good block then re-sleeving an old one. It should not cost to much to find out if it is worth reusing.