What "makes" a 66 Barracuda a Formula S ??

The Formula S was primarily a handling package, brought about by the Rallye Pack option from early 65. It consists of….

HD leaf springs, 6 leaves on the passenger side, 5 on the drivers side

HD “892/893” torsion bars, .870” dia

Front sway bar

14x5.5” steel rims

273 4bbl engine

Dash mounted Tach

Transverse stripes over the roof

High flow exhaust with no muffler, only the resonator

HD 10” drum brakes standard, disc optional in late 65

Formula S side badging on front fenders

As mentioned above, the fender tag for 66 will show a “32” under the “ab”, and a “7” under the “f”. In 65, the 273 4bbl engine designation would be “31” under the “ab”

That’s about it, although I maybe missing some small details.