Overbrook Farm stallion Boston Harbor, who ranks 23rd on the first-crop sire list by progeny earnings, might be headed to Japan. The Lexington nursery, owned by William T. Young, entered into an agreement with the Japan Bloodhorse Breeders Association for the sale of 7-year-old Boston Harbor, but "there are a lot of terms to be worked out," said farm official Ric Waldman. "It may take six to seven weeks."Boston Harbor (Capote--Harbor Springs, by Vice Regent) was champion 2-year-old male of 1996 as an Overbrook homebred. He won that year's Breeders' Cup Juvenile (gr. I) and earned a record amount of $1.9 million for a 2-year-old. Boston Harbor suffered an injury early in his 3-year-old season, and entered stud in 1998 with a record of six wins from eight starts and earnings of $1,934,605. He stood for $25,000 in each season at stud.