1967 Barracuda Formula S 383

Look at the front of the motor...the "flat" below the distributor and in front of the passenger's side head. It should say something like

C 383 HP
2 29

or something like that.

The alpha character in front of the "383" will designate the year car the motor was used in. The "383" is obviously the cubic inch. HP will mean it's a 335 horse motor, and the last 3 digits will be the BUILD DATE of the motor.