For a complete understanding of the Catalina 22 and Catalina 25 swing keel pivot mechanism, start with the first article in this series: History of Retractable Keel Design.
You have eliminated the extra space at the pivot point. Now the excess space must be eliminated at the top of the keel.
It is imparitave this step is completed. eliminating the excess space at the pivot point but leaving excess space at the top of the keel creates another, potentially serious problem: The keel is now properly centered in the middle of the keel trunk by the new hanger castings. As a result, the top of the keel is also centered with no support from the top of the trunk since it is not touching either side. With no support from the top of the trunk, the keel applies a tremendous load to the keel bolts. The bolts must withstand all of the tension created by the laterial force of both the ballast resisting the boats tendency to heal and the keel's lift resisting the boat's tendency to slip to leeward when sailing to weather..
Our keel centering spacer kits (Catalina 22 part #D1996, Catalina 25 part #E1410) eliminate the space at the top of the keel trunk and allow the top of the trunk to support the load from the keel. Shims are epoxied to the sides of the keel near the top. The area where these are placed is visible with the boat on the trailer. When you lower the keel, the forward end of the keel rotates up into the trunk. Now the shims are just where you want them to eliminate the unwanted space.
Both kits include all the materials necessary for installation. The C-22 kit includes two fiberglass shims, one for each side of the keel. With more variation from keel to keel and boat to boat, The Catalina 25 kit is different. It includes six phenolic shims, three for each side of the keel. One, two or three shims are stacked depending upon the amount of space that needs to be eliminated.