C4 · 1984–1996

C4 Options & RPO Codes

The C4's order sheet reads like a comeback story: from the Cross-Fire 205-horsepower restart of 1984 to a 375-horsepower DOHC supercar option costing as much as a second car, ending with the Grand Sport sendoff. Every code appearing in the year pages' production tables is explained here — click a code in any year's table to land on its entry. Engine stamp suffix codes (ZFC, ZJB…) are decoded in each year's engine-stamp table, not here.

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Engines · Special packages · Suspension & brakes · Transmissions & axle · Wheels & tires · Roof, body & mirrors · Seats, interior & electronics · Radios · Export & emissions

Engines

L83 — the Cross-Fire 350

1984 only: the 5.7-liter V8 with twin-throttle-body Cross-Fire Injection, 205 hp — the engine the C4 launched with and outgrew within a year. Every 1984 Corvette has one; no other year does.

L98 — the Tuned Port 350

1985–91: Tuned Port Injection brought the 350 back to life — 230 hp at its debut, 250 by the end, with torque everywhere. The standard heart of the mid-C4 years and the engine that made the car credible again.

LT1 — the second-generation small-block

1992–96: an all-new 300-hp 350 with reverse-flow cooling, reviving the most famous small-block code of 1970. It closed most of the gap to the ZR-1 for a fraction of the price and powered the C4's strongest sales years.

LT4 — 330 hp, manual only

1996, $1,450: the LT1's hotter sendoff — better heads, cam and compression for 330 hp, sold only with the 6-speed and standard in the Grand Sport. The last and best iteration of the Gen II small-block.

LT5 — the ZR-1's DOHC V8

1990–95: the exotic heart of the ZR-1 — an all-aluminum 5.7-liter with four overhead cams and 32 valves, developed with Lotus and built by Mercury Marine. 375 hp at launch, 405 from 1993. It never sold separately — the only way to get one was the whole package. A twin-turbo LT5 also powered the CERV III, and Bertone moved a stock one amidships for the Nivola.

Special packages

ZR1 — the King of the Hill

1990–95: the Special Performance Package — the LT5, the wide convex tail with 11-inch rear wheels, and the FX3 suspension — at $27,016 in 1990, rising to $31,683, an option that nearly doubled the price of the car. The fastest American production car of its day and a code deliberately echoing Zora's 1970 race package. See the 1990 page for its debut year.

Z16 — Grand Sport, 1996

The C4's farewell: Admiral Blue with a white stripe and red hash marks, the LT4, and 1,000 built — $3,250 as a coupe, $2,880 as a convertible per the order sheet. The name honors Zora's five 1963 lightweights, and the code has carried mystique ever since.

Z15 — Collector Edition, 1996

$1,250: Sebring Silver paint — a name borrowed from 1963's one paid-for color — special wheels and trim for the last year of the generation.

Z25 — 40th Anniversary, 1993

$1,455: Ruby Red over Ruby Red, with anniversary badging inside and out — offered on every model including the ZR-1.

Z01 — 35th Anniversary, 1988

$4,795, coupes only: white over white over white — paint, wheels, and interior — with dark tinted roof. One year, one look.

Z51 — Performance Handling Package

The enthusiast's checkbox for the whole generation — stiffer springs, bars and quicker steering, from $600.20 in 1984 to $350 by 1996 as its contents shuffled. Famously punishing in the early years, tamed later, and the ancestor of the Z51 still on the order sheet today.

Z52 — Sport Handling Package

1987–88 ($470–$970): the civilized middle path — much of the Z51 hardware without the punishment.

Z07 — Adjustable Suspension Package

1991–95, around $2,045: FX3 plus the heavy-duty bits — the track-day bundle for LT1 coupes, reviving a 1973 code.

Suspension & brakes

FX3 — Selective Ride and Handling

1989–95, $1,695: cockpit-adjustable Bilstein damping — Tour, Sport, Performance — developed for the ZR-1 and offered on the standard car. The first step toward today's adaptive suspensions.

F45 — Selective Real Time Damping

1996: FX3's successor — sensors adjusting each damper continuously rather than by driver-selected mode. The direct ancestor of the Magnetic Ride lineage.

FE1 / FE7 — soft ride / heavy duty suspension

1989–93: the base calibration menu — FE1 for comfort, FE7 (a Gymkhana-era code) for firm.

FG3 — Delco-Bilstein shocks

1984–88: the premium damper option before FX3 made them adjustable.

J55 — heavy-duty brakes

1990–93: bigger, harder-working brakes for track use.

JL9 — anti-lock brakes

The ABS code on order paperwork, 1989–93 — Bosch ABS II had made the Corvette one of America's first ABS-equipped production cars in 1986, and this is how it showed on the sheet.

Transmissions & axle

MM4 — the Doug Nash “4+3”

1984–88: the C4's strangest gearbox — a 4-speed manual with computer-controlled overdrive on the top three gears. Clever on paper, confounding in traffic, and gone the moment the ZF 6-speed arrived.

MX0 / MD8 — automatic with overdrive

The 700-R4 four-speed automatic under its early code (MX0, 1984–88) and later one (MD8, 1987 on) — the transmission most C4s actually got.

MN6 — the ZF 6-speed

1989–96, no-cost: the German 6-speed built for the ZR-1 program and shared with the base car — complete with the infamous computer-aided 1-to-4 skip shift. Listed under ML9 on some 1990 paperwork.

G92 — performance axle ratio

The shorter-gears checkbox across the generation — the acceleration play, carried over from the C3 years.

The axle-ratio menu

The C4 order sheet listed rear axles à la carte: G44 (3.07), G95 (economy), GH0 (3.54), GM1 (2.59), GM3 (3.45), GT7 (3.33), GU2 (2.73), GW4 (3.31), and G87 (the 8.5-inch ring gear). Highway economy at one end, stoplight urgency at the other.

Wheels & tires

QZD — 16-inch wheels & P255/50VR16

1984–88: the “Gatorback”-era 16-inch setup — unidirectional Goodyear Eagles that were front-page tire news in 1984.

QA1 / QA2 — 17-inch aluminum wheels

1989 on: the 17×9.5 styled wheels (QA1), and the ZR-1-look staggered set with 17×11 rears (QA2, 1990–91).

XAU / YAU / YBE — the Z-rated tires

Tire codes of the 17-inch era: P275/40ZR17 front (XAU) and rear (YAU), and the ZR-1's massive P315/35ZR17 rears (YBE).

WY5 — Extended Mobility Tires

1994–96: run-flats — the technology that would let the C5 delete its spare entirely.

N84 — spare tire delete

1995–96: with run-flats fitted, a credit for skipping the spare.

Roof, body & mirrors

CC3 / CF7 — removable roof panels

The coupe's targa panel: transparent (CC3) or body-color (CF7) — the C4's answer to the glass T-tops, now one piece.

CC2 — convertible hardtop

1989–96, $1,995: the removable hardtop for the reborn convertible — the C07 idea, twenty years on.

D84 — two-tone paint

1984–87: the lower-accent two-tone schemes of the early C4.

V56 — luggage rack

1989–93: deck-lid rack for the convertible.

The mirror codes

Electric outside mirrors under a shifting alphabet — DD9 (1984–88), DC7/DC8 (1991–93), heated convertible mirrors (DL8), and the illuminated vanity mirror (D74).

Seats, interior & electronics

AQ9 / AR9 / A51 — seats

The seat menu: cloth sport seats (AQ9), base leather (AR9), and the 1986 bucket listing (A51). The sport seats' lumbar and bolster adjustments were state-of-the-art in 1984.

The power-seat codes

Six-way power under five codes across the years: AG9 early, AC3/AC1 (driver/passenger) through the middle years, AG1/AG2 at the end. Same comfort, new paperwork.

AJ3 — driver airbag

The inflatable restraint listing from 1990, when the Corvette got its airbag (AS8 marked the 1989 manual-belt cars). Safety equipment arriving code by code.

AU3 — power door locks

Carried over from the late C3; near-universal by mid-generation.

AX4 — European belt system

1984–88: export-specification seat belts.

NK4 — sport leather steering wheel

1989–93: the thicker leather rim.

U19 / U52 — instrument clusters

The C4's famous digital dash generated its own codes: the electronic cluster (U52) and the kilometers-first version (U19). Love it or hate it, nothing else on the road looked like it.

UJ6 — low tire pressure indicator

1987–96: tire-pressure monitoring decades before the mandate — one of those quiet Corvette firsts.

UD2 / UD6 — export alarms

Oddities from the export list: a 105-km/h speed chime (UD2) and an exhaust-temperature alarm (UD6) for markets that required them.

K34 — cruise control

1984–88 as an option, standard later.

K05 — engine block heater

For cold climates, all generation long.

K68 / K09 / KW2 — generators

Alternator upgrades by amperage: 105 (K68), 120 (K09), and 124 amps (KW2) as the car's electronics grew hungrier.

KC4 — engine oil cooler

1984–91: the track-day insurance policy.

V01 / V08 — heavy-duty cooling

Big radiator (V01) and the full HD cooling group (V08).

C49 — rear defogger

The heated backlight, carried over from the C3 code.

C60 / C68 — air conditioning

Manual A/C (C60) and the electronic climate control (C68, from 1986) — the latter one of the earliest automatic systems in an American sports car.

T61 — daytime running lamps

1990–93: the Canadian-market DRLs, before they spread everywhere.

U03 — horn noise regulator

1984–86: an export-compliance hush for the horn. Yes, really.

Radios

UM6 — AM/FM stereo cassette

The base radio of the generation, 1984–93.

UU8 / UQ4 / UX0 — the Bose systems

The Delco-Bose partnership made the C4 an audio flagship: the Bose system (UU8, 1984–93), its speaker package (UQ4), and the six-speaker Gold system (UX0 — also appearing as UXO on some year tables).

UN8 — stereo with CB

1984–85: the CB's last stand, carried over from the seventies.

U75 — power antenna

1991–93 on the order sheet.

UL5 — radio delete

1984–88: still there for the purist, still rarely ticked.

Export & emissions

The export codes

The C4 sold worldwide, and the paperwork shows it: European modifications (VD1), Japanese modifications (VE1), Gulf States (VB4) and unregulated markets (VT7), left-rule-of-road headlamps (T72/T84/T85), European tail lamps (T89/T93), export speedometers (U18), front tow hook (V70), Japanese and European radio frequencies (UK1/UL2), and European glazing (A26). A world-market Corvette, one three-character code at a time.

The emissions codes

California requirements (YF5, later NN5), the assembly-line test (YA7), New York's own listing (NG1), Canadian base equipment (Z49), and the leaded-fuel export modification (NM8) with its Canadian counterpart (NM5).

Paint & trim codes

Exterior colors and interior trims, with production figures where known, are on each year page from 1984 through 1996 — and the C2 and C3 glossaries cover the earlier generations. Spot an error? Tell us.