The XD housing is 300% stronger in end of travel load testing.  The added strength is in the mil-spec alloy housing.  The cap is held securely in place with a hex lock and snap ring.

Make: Chrysler     Taper:1.5"     Ball Size: 1.437"     Cap: Steel XD

Reference: It is based on 65-89 Chrysler, Dodge, and Plymouth design.

Racing Applications: All asphalt late models, TA2 cars, Dirtworks, Troyer Ford steering uppers. Also fits Pinto upper taper.