With GM's IROC license lapsed (the race series moved to Dodge), the plain Z28 name returned for 1991 with a fresh ground-effects facelift. New too was the B4C Special Service package — essentially 1LE-grade hardware in an unassuming RS-coupe wrapper, aimed at sheriff's departments and highway patrols.
The powertrain and identification notes below preserve configuration and model-year boundaries rather than treating every 1991 Camaro alike. Ratings use the measurement convention of their period, and visual cues are only a starting point: the VIN, factory labels, drivetrain identifiers, and surviving documentation should agree.