For a sports car, an American engine was a cop out (OK, the Cobra is an exception). For a grand touring car, not so much.
The Iso Grifo is a great looking car and slots into the same niche as my Jensen Interceptor (also Italian styled as well as built, with regard to the earliest cars and American powered), the Monteverdis, Bristols, Facel Vegas, Bizzarinis, and De Tomassos.