North American P-51 Mustang (N551H)

Good shot of an H. REally hightights the differences from this angle.

North American eventually developed a considerably lightened Mustang, which became the P-51H. With a remarkable top speed of 487 mph, the P-51H was 50mph faster than the P-51D. Although it was in production before World War II ended, the P-51H did not reach front-line units in time to see combat. With the last of 555 P-51Hs completed in 1946, the production run of the Mustang ended with over 15,000 of all types built.

for details see https://museumofaviation.org/portfolio/p-51h-mustang/

-rant on-
i always giggle when i read the prototype of the Mustang, designated as NA-73X and the F4U Vought prototype bearing the factory designation V-166B. FA loves the V-166 but shuns the NA-73x. Both had factory prototype designations and neither used these as an ac type code (NA73 vs V166). 'Freedom of the press' does not insure accuracy but allows all forms of ignorace.
-rant off-

With the FAA N551H is listed as: F-51-H-5-NA, at http://www.joebaugher.com/usaf_serials/1944_4.html shows delivered as North American P-51H-5-NA Mustang.