Heavy-duty brakes (police usage)

Years 1968–72 Models 2 Factory citations 1

Also described as HD brakes (police usage)

Documented applications

Cutlass / 4-4-2

1969 Factory-verified

Factory optional-equipment list: "Heavy Duty Brakes (Police Usage)"

GM Heritage factory kit — 1969 Oldsmobile 442 Info Kit, p.247.

Full-Size 88 / 98

1968–72 Confirmed

Replaces J-56

This page aggregates every documented appearance of J-55 in the Oldsmobile reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.