1) The casting was fit to the boom on the boat during production. There may need to be a small amount of filing done to make the casting fit inside the boom extrusion.

2) Early Catalina 28's used booms sourced from Forespar that require different castings. This casting will not fit the Forespar boom. Parts for the Forespar booms are no longer available.

3) With the advent of rigid boom_vang, Catalina changed the design of the gooseneck. In order to reduce the load on the vang end fittings, the boom no longer rotates. The stainless stud is now fixed in the casting.