The third-generation Camaro was produced from 1982 to 1992. These were the first Camaros to offer modern fuel injection, Turbo-Hydramatic 700R4 four-speed automatic transmissions, five speed manual transmissions, 16 inch wheels, a standard 4-cylinder engine, and hatchback bodies. The cars were nearly 500 pounds (227 kg) lighter than the second generation model.
The IROC-Z (the IROC stands for International Race of Champions) was introduced in 1985 and continued through 1990. National Highway Traffic Safety Administration (NHTSA) Regulations required a CHMSL (Center High Mounted Stop Lamp) starting with the 1986 model year. For 1986, the new brake light was located on the exterior of the upper center area of the back hatch glass. For 1987 and later, the CHMSL was either mounted inside the upper hatch glass, or integrated into a rear spoiler (if equipped). In January 1987, the L98 5.7L 350" V8 engine became a regular option on the IROC-Z, paired with an automatic transmission only, although a limited run of 1,000 late 1986 350" Camaros had been produced. The "20th Anniversary Commemorative Edition" was offered in 1987, as well as a "25th Anniversary Heritage Package" in 1992 that included a 305 cu in (5.0 L) High Output engine. Beginning in 1988, the 1LE performance package was introduced, optional on street models and for showroom stock racing in the U.S. and Canada. The B4C or "police" package was made available beginning in 1991. This basically created a Z28 in more subtle RS styling.
Source: Wikipedia, 2012