General Motors made a 1985 Z28 with the IROC-Z package, which was a high-performance option available for the Z28 model starting in 1985, and they also made a standard Z28 without the IROC-Z package. The IROC-Z was a separate model designation for Chevrolet's race-inspired Camaro, named after the International Race of Champions series.

WA8861 (Dark Huron Blue Metallic

August 2025

An IROC-Z will generally have a greater value than a standard Z28 from the same era, especially in good condition. The IROC-Z was a special, higher-performance version of the Z28 during its production run from 1985 to 1990. 

The Edelbrock Rollin' Thunder Camshaft Kit #22046 is a hydraulic roller camshaft package for 1987-later small-block Chevy engines, designed for street/strip performance in the 1,500 to 6,500 RPM range. Its specifications include 234°/238° of duration at .050" lift, 0.539"/.548" of valve lift (intake/exhaust), and a 112° lobe separation angle. The kit includes the camshaft, hydraulic roller lifters, and pushrods, and is best used with compatible Performer or Performer RPM manifolds and cylinder heads