What made me fall in love with Mustangs hard core was the first time I heard a 96 Cobra fly by me in my 84 GT. To me the Ford 302 pushrod and all their 4valve head mod motors sound better then almost anything else on the planet. Deep growl at idle and mid RPMs and a vicious howl at 6500+ RPM.
That being said there are a few engines that give me goos bumps when I hear them.
Aston DBS and Vantage sound like sex! Just such a spectacular sound!
Forgot about the CCX. Although it really is just Fords good old 4.6 DOHC motor. Later models got their own 4.7 but if you look at the motor you can see its still 90% Ford.