The Ford Mustang faced an identity crisis when it made the switch from its time-tested overhead-valve 5.0-liter V-8 to an entirely new DOHC “modular” eight-cylinder engine family in the mid-1990s.

Goal:Build a 300-rwhp, naturally aspirated non-PI-headed 4.6 Mustang. Result:To Be Determined. Grade:Project not finished yet. Best performance:355 flywheel horsepower/364 lb-ft of torque to date.

Fire up a fourth-gen Ford Mustang GT and you'll hear one of two distinctly different V8 soundtracks, depending on when it rolled off the assembly line. From 1994 through 1995, that rumble came from ...