The second-generation Barracuda, now a 108 in (2,743 mm) wheelbase A-body still sharing many components with the Valiant, was fully redesigned with Barracuda-specific sheet metal styling and its own range of models including convertibles as well as fastback and notchback hardtops.
The new Barracuda was styled chiefly by John E. Herlitz and John Samsen. It was less rectilinear than the Valiant, with coke-bottle side contours and heavily revised front and rear end styling.
Design cues included a concave rear deck panel, wider wheel openings, curved side glass, and S-curved roof pillars on the notchback.
The rear portion of the roof on the fastback coupe was more streamlined, and the back glass, raked at a substantially horizontal angle, was much smaller compared with that of the previous model. Also, the use of chrome trim on the external sheet metal was more restrained.
During this time frame the first U.S. Federal auto safety standards were phased in, and Chrysler's response to the introduction of each phase distinguishes each model year of the second-generation Barracuda:
1967: no sidemarker lights or reflectors.
1968: round sidemarker lights without reflectors.
1969: rectangular sidemarker reflectors without lights.
As the pony-car class became established and competition increased, Plymouth began to revise the Barracuda's engine options.
In 1967, while the 225 cu in (3.7 L) slant-6 was still the base engine, the V8 options ranged from the 2-barrel and 4-barrel versions of the 273 cu in (4.5 L) to a seldom-ordered 383 cu in (6.3 L) "B" big-block, the latter available only with the Formula S package.
Source: Wikipedia, 2012