Introduced in the '05 Mustang GT, the all-aluminum 3V 4.6 V8 offers 300 hp, sounds great, and is able to stand up to some boost and nitrous as long as you don't go too far beyond 450 hp at the wheels. If you're not afraid of cutting shock towers out of an early unibody car, these engines make good swap candidates. Ford Racing offers a crate version with a stand-alone ECM. If that's too rich for your blood, look for a used version online. If maintained well, these engines run for more than 100,000 miles. .