The HIN on a KP44 or KP46 is usually located on the starboard transom near the cap rail.  The HIN typically is a 12 digit code that looks like this:

Manufacture's Code (JKY, for "Jack Kelly Yachts" or FBB for "Formosa Boat Builders")
Model Number (44 or 46 )
Hull Number (or "Line" Number), 3 digits.  This starts with 101.  I.e. the first KP44 had hull number "101".
Date hull was commenced (MMYY)

E.g.

is a Kelly Peterson 44, Hull 276, hull date of Feb 1980.

E.g.

is a Formosa 46 ( Hull # 86, hull was commenced in October 1986. F46's were made from 1979 to 1986.