An engineer has spent the last 11 years transforming a 1984 Ferrari 308 GTS QV in his garage into what he calls the FrankenFerrari. The sports car features a custom Ferrari 5.4 L V12 estimated to make around 920 horsepower and 500+ lb-ft of torque when finished and tuned. The engine consists of a 4.8 L F101 D V12 engine block from a Ferrari 400i with the bore increased from 81 m to 86 mm and Ferrari 360 titanium connecting rods. On top you find modified flat-twelve heads from a Ferrari Testarossa with custom camshafts, larger valves, and Ducati 999 54 mm throttle bodies. The dry-sumped engine is mated to a modified 308 transaxle with a custom billet flywheel, 360 ring gear, Chevy starter, and Tilton 7.25-inch 3-disc carbon clutch. If you enjoy reading detailed build thread, then you will love reading all the details on the Grassroots Motorsports build forum.
Update 1-23-19: For even more details please visit the owner’s forum where he documents all the work on the Ferrari and his other projects.
Source: Grassroots Motorsports (build thread) and Mark Gemellocattivo
btw this being roughly a year old now.. read through the forum a little, and to me it seems while the maker has access to exquisite tools and knows his hands around CAD, he seems to lack basic understanding of metallurgy and engineering. So much welding on parts with varying thickness, no stress relieving anneal… those cylinder heads seem to be half welding rod by now. Seems to rebuilding the whole engine right now after only a handful of starts