Heavier body styling gave 1971-73 Cougars a more mature look when compared to earlier models. A boldly prominent center grille and newly exposed headlamps dominated the fresh frontal appearance. A GT appearance/handling option was revived for standard models, while extra-posh XR-7 models topped the line. During 1971-73, a 351-2V V-8 was standard in the Cougar. The 370-hp 429 CJ (production: 448, including 47 convertibles) was offered only in 1971. A regular-fuel 351 CJ V-8 debuted mid-1971 and continued as an optional 4V engine through ’73 — essentially, it was the regular 351 4V engine with sporty sounding dual exhausts. After carrying over the ’71 Cougar with little change for 1972, Mercury introduced the 1973 models with a federally mandated impact-absorbing front bumper. The 1973 Cougar was the last built to the original ponycar-in-a-sport-jacket concept. With 3,165 built, the 1973 XR-7 Convertible was the most popular Cougar drop-top ever. Among the 1971-73 Cougars, the 429 CJ cars are the most sought-after by collectors today. The scarce 1971-1973 Convertibles offer open-car fun and V-8-power at relatively affordable prices.