The mounting hole pattern and lower
shroud clevis pins are designed to match the original locations, so there is no need to drill new holes in the mast or replace rigging.
The very early Catalina 30 used a different mast than subsequent boats. The early mast had a stainless steel mast track added to the spar after it was extruded. Later boats had an internal track extruded into the mast. Early masts also used welded spreader brackets with different spreaders than later boats. We know that hulls through at least #337 were built with this mast. Unfortunately there is no official record of the exact hull number when the mast changed so check your mast carefully. This kit does not fit those very early boats with welded brackets. It is compatible with masts on boats after approximately #337 that have sail track extruded as an integral part of the mast.