This Fiat 125p was built by Classic Cars Garage in Kingscourt, Ireland over the course of three years. The project started by replacing the factory 1.5 L inline-four with a Mercedes 3.0 L inline-six. However that quickly changed and the inline-six was replaced by a 5.8 L Ford 351C V8 from a Mustang Mach 1. The V8 engine is mated to five-speed manual from a Mercedes 300SE. The car rides on a Jaguar XJ12 front and rear suspension with a set of BMW wheels.
Source: SL Modifications FB page via Piotr