That clip fits in the small groove on the guide, that is the stop for how far the guide seats in the head. I never use oem guides so it took me a bit to realize what you were talking about. Aftermarket guides just machine a stop directly into the guide and dont use the clip. Keep in mind, if you replace the guides you will have to do a valve job after replacement, the valve will no longer be concentric with the seat after the swap. Also be sure you get all the carbon out of the port side of the guide before driving them out or you can badly score the bore in the cylinder head which will cause issue installing the new guide which is a press fit.
