The C36IA "Tool Box" actually has 3 sizes of keel bolt sockets that we have collected over time. I supect over the 23+ years of manufacture that Catalina has changed the spec's of the keel bolts slightly.

The 3 sizes we have are 15/16", 1" and 1-1/8" -- I can tell you that you will probably need an extra long deep socket. The typical 3" deep sockets one finds at a hardware store will probably not work. The sockets I have are 4-1/2" - 5" deep (hand fabricated from 2 sockets and welded together)

I have verified that Keel bolt sizes on later C36's MKII are 1-1/8" (my 1999 hull # is 1800 and is 1-1/8")

The specified Torque for Keel Bolts is 105 ft-lbs.