You are correct in that it can be done but that is a factory process that has to be carried out meticulously. The coating has to be re-applied back to the aluminum. I gather the original person that posted is assuming he can take the DIYer home drill honing kit and clean up the walls of the block. If his block is scored then it would have to be sent back to one of those special machining process companies(i.e factory processing) to have the block re-done and then your looking at huge dollars. He would be better off finding a used engine/donor to do the rebuild.