Metric Chassis Steering and Brakes

The term “Metric Chassis” commonly refers to the intermediate line of
GM cars built from 1978 through 1988 including the Chevrolet Monte
Carlo and Malibu, Oldsmobile Cutlass, Buick Regal and the Pontiac
Grand Prix. These chassis are very similar but they also have some
differences. One of the major differences applies to the front steering
spindles and brake rotors. There were three different brake rotors
used and two different spindles. 1978 year vehicles used a spindle rotor
combination that was a one-year production. 1979-88 vehicles used the
same spindle but utilized two different brake rotors. These rotors appear
very similar but the 1979-81 use a brake rotor with a larger outer
bearing and race than the 1982-88 model years. These rotors may be
interchanged but will require the matching outer bearing for proper
installation.

Information Courtesy of Allstar Performance