Drum Brake Substitution (credit)

Years 1963–79 Models 2 Factory citations 1

Also described as Disc brake delete

Documented applications

Corvette (C1 / C2)

1965 Factory-verified

-$64.50; 316 built; 4-wheel discs became standard in 1965, this credit deleted them (J56 was not offered in 1965)

GM Heritage factory kit — 1965 Chevrolet Corvette, p.14.

Impala / Full-Size

1963–70s (varies) Single-source

This page aggregates every documented appearance of J61 in the Chevrolet reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.