Stock column and a Mustang rack that won't talk to each other?

This gives the original column the shaft and joints it needs to turn the rack. There's a vibration-damping joint at the rack end, and the double-D shaft connects the two joints.

Fitment

Ridetech 12319505 connects the stock steering column to a 1979–1993 Mustang rack in Ridetech’s 1965–1979 F-100 front suspension system or 1967–1969 Camaro/Firebird subframe.

Specs and included parts

Rag-joint-to-1-inch-DD adapter; 1-inch-DD × 3/4-inch-DD U-joint; 12-inch length of 3/4-inch-DD shaft; vibration-damping 3/4-inch-DD × 3/4-inch-36-spline U-joint; hardware. Part 12319505.

I drop-ship to shops anywhere. Just ask.