Yes, the P-51 is a dweeb plane in the game like the Spit. The sounds these aircraft make in real life are unforgettable. HTC is this possible in the game?
First off, your premise is mistaken. Dweebery comes from how you fly, not
what you fly. Anyone that thinks otherwise is still a dweeb.
To answer you final question, yes and no. Yes, you can make it whistle. No, it won't sound real if it does. So, everything you use will be a tradeoff between sounding good in the cockpit and sounding good from the ground. Because of the way DirectX uses and portrays sounds it is not possible to make it perfect for aircraft. The reason is very simple, they just have too wide an operating range. That's why you can have a dozen different sound packs with optimized sounds that all sound different.
Vehicles are another story.