Jimmy, If you don't mind a short and explosive engine life, you can bore them out and put a block girdle on them like the pullers do. So far as I know there was only one situation where you could bore out a Kohler engine to a larger size. Some of the K241's were made from K301 castings. They would have K241 on the shroud but K301 on the block. Those could be bored out to the K301 diameter.