dude he has a 93 900SS...Some replacement guides claim to be installable with no need to ream. However, to trust that without a way to accurately make sure they have not distorted during installation is risky IMO. Be very careful about how they feel when you put the valves in. Heat soaked engines, such as during a track day, run the risk of sticking a valve so this is a critical repair. Race and track day bikes can be better off leaving the exhaust valve seals off. Seating a non shouldered guide too far can cause problems. The shop should be willing to talk about how they set them up so you aren't going to go off and stick a valve. If you run your bike on the track, be sure to tell the shop that the bike will be run at high continuous power settings for 20 minute sessions.