What one Ferrari owner thought would be a simple swap turned out to be an 11-year project that continues today.

Grassroots Motorsports forum user Mke detailed his lengthy battle to swap a V-12 engine into his Ferrari 308 GTS, which Road & Track reported this past January. It's not the first time someone has tried to stuff a V-12 into a 308, but this owner's journey is far more interesting and downright incredible.

The V-12 came from a junked Ferrari 400i, which the owner thought would be interesting to fit with quad-valve heads from a Testarossa. Right away, he discovered the heads didn't match with the 400i V-12's block. The bolt holes didn't align and the oil paths were far from lining up. Instead of giving up and looking for different heads that would bolt up, Mke decided to fashion something himself—for over a decade.

The owner proceeded to cut and re-weld the heads to make them match up with the V-12 block and fit snugly in the 308 GTS's engine bay. There's a lot of incredible fabrication work going on here. The engine now displaces 5.4 liters, due to its increased bore. The titanium connecting rods are sourced from a Ferrari 360 Modena. The individual throttle bodies once called a Ducati 999 motorcycle home. It's all truly astounding. 

That's not to mention the custom camshafts, dry-sump oil system, or larger valves the builder retrofitted. Power still heads to the rear wheels and meets a three-disc carbon clutch and bulkier transaxle. How much power? Estimates show the engine will make 900 horsepower when it's running all and well.

Today, the engine is only firing on 11 cylinders, according to the forum post, but Mke hopes that one day he'll have the car totally drivable. Keep on keeping on, Mke. We commend your patience and diligence.