Oui le moteur est la principale différence. C'est le Merlin qui a fait du mustang la légende qu'il est devenu. Et le merlin apparait avec le P51B/C.
Tu peux voir facilement la différence au nez de l'avion. Le P51A a une petite prise d'air sur le dessus du pif, et aucune en dessous, alors que le P51B n'a plus la prise d'air au dessus du pif, mais en dessous tout comme le P51D. Tu peux voir la différence sur les profils postés ci dessus.
Les P51 (Mustang IA) anglais étaient équippé de 4 canons de 20mm. Je veux ça dans FB
Tiens ça c'est bonus:
"The Allison Mustangs did not do well in the air combat role, as they were at a disadvantage against their primary adversary, the agile Nakajima Ki-43 Hayabusa, known to the Allies as the "Oscar". Although the Oscar had significant weaknesses, being under-armed and lacking in armor protection, the Mustangs got the worst of it in their clashes with the Japanese fighter over Burma.
These missions were, however, the first use of the Mustang as a long-range escort fighter, with P-51As carrying two 284 liter (75 US gallon) drop tanks and flying round trips from Kurmitola in Bengal to Rangoon in Burma, 725 kilometers (450 miles) away. It was a hint of things to come.
The Mustangs did well at reconnaissance and close support missions. One P-51A outfit, the 1st Air Commando group, was assigned to provide close support for Orde Wingate's British Chindit warriors in Burma, and operated in the field at rough airstrips to keep up with the battle. They sometimes carried 450 kilogram (1,000 pound) bombs, or the three-tube 11.5 centimeter (4.5 inch) M-8 "bazooka"-style rocket launchers.
The 1st Air Commando group was led by Lieutenant Colonel Philip Cochran, a legendary old China hand who was well-known to the American public through the cartoon character "Flip Corkin" in Milton Caniff's TERRY & THE PIRATES comic strip. Although details are sketchy, the Allison Mustangs appear to have operated in the CBI well into 1944, when they were replaced by P-51Bs."
Source :
http://www.faqs.org/docs/air/avp51.html
Nico