Straight from Boeing:
On July 27, 1989, an Air Seychelles 767-200ER set a new distance record for a commercial twinjet--flying 8,893 statute miles (14,309 kilometers) from Grand Rapids, Mich., to Seychelles in 16 hours and 49 minutes.
On June 10, 1990, a Royal Brunei 767-200ER set a new distance record for twinjet airliners--flying 9,253 statute miles (14,890 kilometers) from Seattle to Nairobi, Kenya, in 17 hours and 51 minutes.