My 04 with 50K still has originals. They were fine a 30K. Would not hurt changing them. Delrin gets brittle from hot oil. They could brake if you drive it hard and rough. There is no upgrade unless you do cams since Harley's SE does not replace the inner link chain. Hydraulic tensioners on a link chain are worst then the spring tensioners.

Two shoes, some gaskets and orings. Check OP before going in. Inspect inner cam bearings or replace and check oilpump with precision tools. Then for 300-400, you are good for another 20-40 years.