The Galloping Ghost is only the fourth racing P-51 to undergo this surgery. If done right, it has some big benefits to offer.
Galloping Ghost, Strega, Voodoo...I can't recall the last...Miss America II?
The unlimited racers that win are all highly modified from their original form - bubble canopy removed, cooling scoop removed, wings shortened, aerodynamic tweeking and mechanical tweeking so that the Merlin's output is 3800 horsepower plus...twice that of the stock version.
Video of Strega qualifying last year at 484 mph (499 this year). Water/meth vapor clearly visible.