1966 Barracuda wheel size

Gorilla Automotive 71178L, set of 4, 7/16-20LH, 60° conical seat, steel/chrome, 13/16 wrench.

Gorilla Automotive 71177, set of 4, 7/16-20RH, 60° conical seat, steel/chrome, 13/16 wrench.

Summit racing has them for $6.97/set