You really need to check your cylinder wall clearance first and make sure the block doesn't need to be bored. Since you are already seeing a ridge, that should tell you that you have enough wear that honing them may be a moot point. As for the grit, it depends a lot on the rings you will be using, but even for cast rings the 180 is a little too rough unless your doing a "shadetree" rebuild. You also need to inspect and mic the pistons to make sure they are going to be reusable.
