Harry Metcalfe has been chronicling the restoration of his Jaguar XJC V12 since 2021. The car recently received a new fuel-injection system and ECU. Naturally, he wants to know how much power the beautiful coupe is putting down now, so it's time for a dyno run. Then, the rejuvenation is officially complete.

As the name implies, the XJC is the coupe version of the Jaguar XJ, specifically the Series 2 version of the sedan. Power comes from a 5.3-litre V12 and routes through a manual gearbox in this case.

In stock guise, opening the bonnet of a V12 Jaguar reveals an ugly scene. There are vacuum lines and various pipes everywhere, which takes away from seeing the big engine. The restoration work on this one includes tidying up things to create a more aesthetically pleasing appearance.

Originally, the 5.3-litre V12 made 285 bhp and 294 pound-feet of torque, according to a brochure that Metcalfe shows in the video. With the overhauled fuelling system, this one is now putting down 350 bhp and 374 lb-ft. These are gains of 23 percent more power and 28 percent more torque.

On the road, the car has a Jekyll and Hyde quality. When cruising, the engine is quiet, but above about 4,500 rpm, it begins to scream. Having the manual gearbox is especially nice because dropping a few cogs lets Metcalfe immediately get to enjoy the amazing sound.

The last part of the video just shows Metcalfe driving and enjoying his freshly restored XJC. It looks like an amazing experience.

The Jaguar XJC is quite a rare model because of its limited production run from 1975 through 1977. Power comes from either a 4.2-litre inline-six or the 5.3-litre V12 that's under the bonnet of Metcalfe's example. The design has no B-pillar, which creates a large greenhouse when viewing the coupe from the side. The company made around 10,000 of them total, but only around 1,800 had the V12 engine, according to Metcalfe in an earlier video.