The Ford Mustang came equipped with a V-8 that produced a whopping 225 hp with a 4-barrel carb. The P-51B/C model came with a Rolls-Royce Merlin (built under license by Packard) and produced 1490 hp.

The Ford had 289 CID which is equal to .78 hp/cid. The P-51 had a hp/cid ratio of .90 with 5.7 times the cid of the Ford. With a few engine mods, you can get the ford to give you a hp for every cubic inch. The air racing merlins can give out 2 or more hp/cid!

The only problem is that these racing merlins do not last very long. Something usually breaks and when that happens it is usually very big, like a hole in side of the crankcase.