RE: Ryobi 31cc twin ring & Frank Bowman ring
Mike,
Yes, it is important that the rings are reinstalled exactly as they were. They "wear in" at the location they were running. Also, for the same "wearing in" reason, used rings should not be used in a new bore. You need to go ahead and use the new rings. It wouldn't hurt to ask Frank exactly what finish he likes on the cylinder walls for the best breaking in of his rings, and apply that grit finish to your cylinder. Another hint; do not use synthetic oil for break in. It can glaze the cylinder wall and prevent the ring from ever breaking in properly. Result, blow by and poor compression. If you want to use synthetic oils that is fine, but break them in with a good quality petroleum oil first.
Good luck,
AV8TOR