The third-generation Mustang was produced from 1979 to 1993. Built on Ford’s ubiquitous Fox platform, it evolved through a number of sub-models, trim levels, and drivetrain combinations during its production life.
Carrying a far more powerful and refined 2.3 L turbocharged inline-4, the Mustang produced initially 175 hp for 1984, uprated for 1985 models. It sported handling and braking abilities that would humble a Mustang GT. Four-wheel disc brakes, 16-inch specific wheels, and an SVO-specific bi-plane rear spoiler were just a few of the notable differences between the SVO and the rest of the Mustang line. However, the steep price, which was thousands more than a comparably equipped V8 GT, put off most potential buyers.
In 1985, the Mustang GT got new E5AE cylinder heads, a revised Holley four-barrel carburetor, a new and more aggressive roller camshaft, less restrictive exhaust manifolds, and a pseudo dual exhaust which brought more power to a conservatively rated 210 hp engine. This would be the last carbureted V8 in the Mustang. Also, 1985 saw the departure of the L and Turbo GT, leaving the LX, GT, and SVO.
Source: Wikipedia, 2012