B Body 12" spindle interchange information.
Under construction!
The 1977-1996 GM B Body cars came with several different brake and spindles.
The 12" brake rotor is often found on 9C1 Police, Station Wagons, Impala SS and "Trailer Tow" package vehicles. These bigger brakes can be swapped to other GM cars with the correct parts. This page will try to identify all the different parts and combinations.
1977+ Caprices and other GM "B" body clones could be had with the normal 11" disc brakes. These cars have the "normal" 5 x 4-3/4" bolt pattern.
All 12" disc brake cars have the 5 x 5" bolt pattern except for Camaro with 1LE option.
1977 B cars have the smaller out wheel bearing. Starting in 1978 the wheel bearing was enlarged to xx""
1979 X body (Nova, etc) upgraded to the larger outer wheel bearing on the 11" disc brake spindle.
1976-1979 Cadillac Seville use 12" disc brakes and 5 x 5" bolt circle rotors.
1996 Impala SS spindles are machined for 5/8" ball joints. All Impala SS have 5 x 5" bolt circle wheels.
12" rotors do not fit on 11" spindles regardless of bearing size. The caliper bracket is farther away from the spindle to accomodate the larger diameter rotor. You must use the correct 12" spindle.
This is a 1978 B body spindle for 12" brakes and 9/16" lower ball joint
Front view
The distance between the ball joints on the 12" spindle is 8.700"
last update=1/28/03