They correspond to the assembly 27 in the exploded view of the fresh water cooling system and includes the following components.
28) Flange
29) Bearing
21) Nipple
27) Pump housing
32) Gasket, paper
33) Seal
34) Impeller

OEM Equipment ofor the following engine models (and the boat that we are aware used these engines... There could be other combinations as well):
• M-25XPB (Catalina 28 MkII, Catalina 30 MkIII, Catalina 310)
• M-35B (Catalina 34 MkII, Catalina 350, Catalina 36 MkII)

• Barb, input, large: 1-1/4"
• Barb, output, small: 3/8"
• Flange, item #28, diameter: 2-1/4"
• Impeller, item #34, diameter: 2-1/4"