Also described as Performance axle ratio (dealer ordering code)Performance axle ratio (4.10:1)Rear Axle - Performance RatioRear axleAppearance package, exterior trim, black out
Documented applications
- 1970–1972 Factory-verifiedGM Heritage factory kit — 1971 Chevrolet Chevelle, p.31.GM Heritage factory kit — 1971 Chevrolet El Camino, p.58.
- 1971 Factory-verified
$12.65; 2,395 built. Code was disputed (CAC/CorvetteStory split ZQ9 vs ZQ1). Factory kit resolves: the price schedule (p.70) lists economy axle **ZQ8** and performance axle **ZQ9** at $12.65 each — "ZQ1" does not appear anywhere in the kit
GM Heritage factory kit — 1971 Chevrolet Corvette, p.70. - 1972 Factory-verified
$12.65 (early-year $12.00); 1,986 built. Code was disputed (CAC = ZQ9 vs CorvetteStory/CorvSport = ZQ1). Factory kit resolves: the price schedule (p.76) and Extra Cost Equipment list (p.98) both show economy **ZQ8** / performance **ZQ9** at $12.65 — "ZQ1" does not appear in the kit
GM Heritage factory kit — 1972 Chevrolet Corvette, p.76.
- 1963–70s (varies) Confirmed
Performance ratio
- 2017–2019, 2021–2022 Factory-verified
2017: LT: O; Base, WT, Z71: not offered; LT: with PDB (2017–2018) or WGQ (2018); 2018 from GM's 2018 Colorado order guide (PDF); 2021 from the upfitter list GM files for 2021 and 2022
This page aggregates every documented appearance of ZQ9 in the Chevrolet reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.