Grifo 7 Litri was introduced, featuring a Chevrolet L71 big-block engine, a Tri-Power version of the 427 engine. The massive power plant required several mechanical changes to the car in order to fit, i.e. strengthened chassis components as well as an enlarged engine compartment with reinforced mounts. A large hood scoop (dubbed "Penthouse" due to its size) was added to clear for the engine's deck height. It produced an officially advertised minimum of at 5,800 rpm. The factory claimed the 7 Litri could attain a top speed of . In 1970, a styling change was made to the nose section of the car for the Grifo Series II. It was given a sleeker look and hide-away headlights. In the IR-9 "Can Am" version, the engine was switched from the 427 engines to the newer, even more powerful Chevrolet 454 7.4 litre engine. In 1972, the Grifo IR-8 was introduced, using a small-block Ford Boss 351 engines. These models can be recognized by their taller hood scoop. This was the final Iso automobile made, as Iso S.P.A. closed its doors in 1974 during the 1970s oil crisis. Production In total, 330 Series I and 83 Series II cars were built for a total of 413 cars, 90 of which were 7-litre versions. The rarest are the Series II 5-speeds (23 units) and the Series II Targa (4 units). Due to their rarity today Grifos are desirable collectibles. A former employee of Iso, Roberto Negri, runs a small company in Clusone, Italy, specializing in maintaining and restoring Grifos. See also Bizzarrini Strada Ferrari 250 GTO De Tomaso Mangusta Ferrari Daytona Lamborghini Miura Maserati Ghibli References Sources Automobil Revue, catalog numbers 1963 through 1974 Winston Goodfellow: Iso Rivolta, The Man, The Machines. Motorbooks International 2001. . External links http://www.isorestorations.com/ The Red Grifo - Iso Grifo documentary short film G Rear-wheel-drive vehicles Coupés 1970s cars Cars introduced in 1963 Grand tourers