The car developed 390 hp (290 kW) in its production form and could reach 110 km/h (68 mph) in first gear. Renzo Rivolta also showed a one-off Grifo A3/L Spyder at the Geneva auto show. The production of Iso Grifo GL started in 1965. In October 1966 the very first Grifo (car #97) with Targa Top was shown at Turin. This was one of 13 Series I Targas ever built; later, four series II Targas were built.
In 1968 the Grifo 7 Litri was introduced with a Chevrolet L71 big-block engine, a Tri-Power version of the 427 engine. This seven-liter power plant required changes to the car to fit, and a hood scoop was needed because of the engine's height. It produced 435 hp (324 kW) at 5800 rpm and the factory claimed it could reach a top speed of 300 km/h (186 mph). This particular 7 Litri is still lost.
In total, 322 Series I and 78 Series II cars were built for a total of 413 Grifos, 90 of which 7 Litri. The rarest are the Series II 5-speeds (23 units) and the Series II Targa (4 units). All Grifos are desirable because of their rarity. A former employee of Iso, Roberto Negri, runs a small Company in Clusone, Italy, restoring Grifos.
