C4 Buyers GuideMost folks don’t remember much about the 1984 C4 Corvette. Long since overshadowed by the C5 and its successors, we forget that when it was introduced in March of 1983, it took the automotive world by storm.

After all the fuss over the special edition Silver Anniversary and Pace Car Corvettes five years earlier in 1978, you would think Chevrolet would have leveraged the ‘Vette’s 30th anniversary with a big bang. Instead, only 44 production 1983 Corvettes rolled off the Bowling Green, Kentucky assembly line, and then Chevrolet jumped ahead and designated the new C4 as a 1984 model.

Maybe the anniversary was downplayed because GM didn’t want any distractions to what was the first clean sheet Corvette since the 1960s, and the first to be authored by a team headed by its new Chief Engineer David McLellan. Styled by Jerry Palmer, the new car was loaded up with innovative new technology of the day. Unidirectional 16-inch tires, rack and pinion steering, forged aluminum suspension pieces, drivable chassis, electronic instrumentation and massaged aerodynamics may seem mundane today, but it was a big deal coming out of the malaise era ’70s.

The build quality of the C4 was also head and shoulders over the C3, and ditched the decades-old fiberglass body on a truck like, steel frame, in favor of sheet molded compound (SMC) panels attached to a “Uniframe” space frame.

The C4 was a sales sensation and just the halo car Chevrolet needed to march into the Reagan-era ’80s. It re-established the Vette (and GM) as one of the world’s premier makers of sports cars. In fact, most car magazine reviews back in the day breathlessly proclaimed the new Vette as the best performance car in the world.

The C4 also heralded the beginning of continuous upgrades and improvements that we still see with today’s modern Corvette. Gone were the days of carry-over models languishing with yesterday’s technology year after year, and replaced with yearly upgrades and multiple performance models in addition to a base car. In its 12 year run, the car saw the addition of several versions of the 350 V8, the return of the roadster body style, the “King of the Hill” ZR1 with a 32-valve motor, and numerous styling and suspension tweaks.

The C4 was also an incredible performer. Its new mono-leaf suspension coupled with sticky uni-directional Goodyear tires put everything on the trailer back in the day. So impressive was the new Corvette’s track success, arch rival Porsche rushed back to Germany and essentially “C4’d” its dowdy 944 with big gumball rubber and suspension tweaks to be competitive with the new kid on the block.

Fast-forward to today and the C4 Corvette has remarkably become the red-haired step child of the Corvette hobby. The comparatively primitive C3, with its Bill Mitchell styling has eclipsed C4 values and the C5 (now pushing 20 years) is a compelling argument to go with the newer Vette when looking at used models. The C4’s huge doorsills, blinking dashboard, costly to repair clamshell hood and an appetite for expensive tires hasn’t helped either.

Hold On A Minute, Let’s Not Be So Hasty…

There are many things to like about the C4. The body style has gotten prettier with age and some would arguably say that it looks better than the lozenge shaped C5. It has a good stance and looks especially sinister coming down the road towards you. The car became a nice daily driver after the brittle suspension of the early models were revised and other details were massaged out over its model run. Nice examples can be had for around $10,000 – making the C4 a great way to join Chevy’s sports car family. It’s also a Corvette for God’s sake.

So, without any further ado, here’s a brief overview of the C4 Corvette and what to look for if you’re in the market for this underappreciated ‘Vette. We’ll break it down into two sections, L83/L98 equipped 1984-1991 models, LT1 equipped 1992-1996 cars as well as special editions models i.e. ZR1, Grand Sports, Pace Cars, Anniversary Editions, etc.

C4 Corvette Purchasing Cheat Sheet – What To Look For When You’re In The Market

Uniframe Integrity – The C4 ushered in a new era of material and body assembly for the Corvette. The body panels are essentially non-structural and attached to drivable space frame. Make sure you check fit of these panels as misalignment might be a tell-tale sign of an accident. Always insist that any car you’re interested is lifted up on a hoist so you can poke around under the body and check for corrosion. Now is the time to check for any damage and frame integrity. While the car is up in the air, do a visual check on the internal side of body panels, too.

Clamshell Hood Alignment – This is a huge and complex body panel. Extending down to mid-fender on both sides, a front fender bender can be expensive as the hood is usually involved. There was a reason the C5 ditched this feature.

Battery Door On Lower Drivers Side Front Fender – If this shows signs of wear and tear from being removed a lot, this a good sign of electrical problems.

Removable Top – The C4 ditched the T-Tops of the C3 and employed a Porsche Targa-like single panel with both solid and clear units available. Inspect the panel for cracks, especially where the mounting hardware is attached. Be sure and check signs of leakage which usually can be cured by tweaking alignment or replacing weather-stripping.

Tires – 1984 ushered in modern tire technology making the days of $100 apiece 15 inch BF Goodrich radials a thing of the past. A cost of $2,000.00 is a starting point to replace a set of tires and many sellers will put car up for sale before they have to deal with it.

LT1 Engine Issues – The OptiSpark ignition system on these cars can be tricky. Moisture is usually the cause, resulting in rough running engine or a no-start situation. Be sure to ask seller if the Opti-Spark has been replaced.

Wheel Bearings – C4 Corvette wheel bearings need maintenance. They’re in a sealed hub and are known for prematurely wearing out. If they haven’t been replaced in the last few years, they’ll at least need to be inspected, and probably replaced, just to be sure.

Drivers Side Carpet and Seat – The C4’s high door sills are famous for their tricky ingress/egress. They’re known for wear due to contorting oneself to get in and out of the car. Look at the leading edge of the bulkhead carpet and outboard seat bolster. Replacements are as plentiful as cats and dogs, but they ain’t cheap, especially leather seat covers.

Electric Dashboard –Be sure and check out if the gauges are accurate and everything is working. Problems can be fixed but are time-consuming and expensive.

Steering Column – The aforementioned tricky ingress/egress issues usually take a toll on the steering column as it is leveraged to get out the car. Check for up and down play.  It can be a laborious fix and time is money.

Make Sure Car Is Complete – A unaltered car in well-maintained condition usually brings the most money, but don’t overlook an otherwise good car because it’s been “breathed” on or had owner modifications. The good news is that there is a vast Corvette aftermarket supplier base that would love to help you restore your C4 Corvette. Also, as a general rule, a color change is a deal-breaker for a lot of folks, so find a car that is painted in a factory color that turns you on.

Verify VIN And Motor Numbers – This is fairly easy to do. Some research is required to get up to speed on VIN and engine codes, but definitive guides are widely available.

Get A Used Car Check – The Corvette is exotic, but isn’t immune from mere mortal system checks. Check fluids, do a compression test, check the cooling and electrical systems, check the brakes, steering linkage, and other common safety items so when you drive home you don’t end up in a ditch. If you can do this yourself, great, if not hire a reputable mechanic; preferably one who is familiar with Corvettes. While you’re at it, check every single light, knob, blinker, speaker, etc., to see what’s working and what isn’t. If you really want to be thorough, hire a ‘’Vette guru who can give you a detailed report card on the car of your dreams. A CarFax is money well spent, we think.

Test Drive – This is a must. Be careful not to let the owner run a monologue about the car as you drive. Turn off the radio and take the car on side roads and the freeway. Take note of any clunks, smoke, valve train noise, or sloppiness in the steering, transmission, or brakes.

Take Your Time – Chevrolet built more than 350,000 C4 Corvettes! Most have survived. Take your time, look around and don’t buy the first car you see.

Anticipate Ownership Costs – You’ve got to store, insure, and maintain a 30-year old automobile. Create a tally of what your monthly costs will be to participate in the Corvette hobby without going broke.

Get Educated -The scope of this article is a broad overview of the C4 Vette model run. We strongly suggest reviewing several Corvette “Bibles” to thoroughly educate yourself on rare options, colors and production numbers. Corvette Online has researched the best of them for you here.

Well-Served By Aftermarket – Check out Zip, Corvette Central, and Mid America Motorworks for an extensive selection of parts and mods.

Model Years 1984-1991 (L83/L98 Engine)

1984 – The 1984 model is unique in that it carries over the 205 hp , “Cross Fire Injection” 350 ci motor from the outgoing 1982 model. Unlike its predecessor, the L83 could now be ordered with a Doug Nash 4+3 manual transmissions. Just under 6,500 ‘Vettes were equipped with this gearbox making it a rare car for the 1984 model year. Over half of 1984 production was equipped with the Z51 suspension upgrade. Make sure you all your fillings are in good shape as this is one rough riding, canyon carver.

Nonetheless, the 1984 Vette was a huge sales success with a model starting in early March of 1983, 51,547 models were sold. The undesirable Cross Fire motor, new model teething issues and the huge number produced have hurt 1984 C4 values. No matter, if you can find a good one cheap, we can’t think of a better track car or budget entry to Corvette ownership.

1985 – With the huge splash Chevrolet made with the C4 introduction, you would think they’d rest on their laurels for a few years and catch their breath. Instead, the 1985 Corvette replaced the 205 horsepower L83 engine with the L98 230 horsepower engine with Bosch tuned port fuel injection. Torque also increased from 290 lb-ft of torque to 330 lb-ft.

The rough riding suspension complaints were addressed with a with a 25 percent reduction in spring rates and the new Z51 package now came with 9.5-inch wheels all around, Delco-Bilstein gas-charged shock absorbers and thicker stabilizer bars. These new features kept sales red hot and Chevy moved 39,729 units.

1986 – This was a big year for Corvette as a convertible was now available for the first time since 1975. The ‘Vette was also anointed the pace car for the 70th running of the Indianapolis 500 and all 7315 convertibles produced were considered “pace car” replicas. Additional frame reinforcements were added to stiffen the topless version of the car and were adopted in later years by all models. Horsepower was bumped five hp to 235. New aluminum cylinder heads, ABS, a center mounted brake light, and VATS security system (a chipped ignition key) was now standard. Production cooled off with sales down by 10,000 units to 27,794 cars sold.

1987 – The 1987 ‘Vette got new roller valve lifters boosting output to 240 horsepower. A new Z52 sport handling package included some of the Z51 components with the softer base model suspension. Also included were a radiator boost fan and heavy-duty radiator, engine oil cooler, Bilstein shock absorbers, larger 16 x 9.5 in. wheels, thicker front stabilizer bars, 13:1 steering ratio. Both the Z51 and Z52 options included new structural enhancements to increase rigidity, borrowed from the convertible. Sales bumped up to 30,362 with more than 10,000 built as convertibles.

A new option B2K could be specified and when ordered the finished Vette was shipped to Callaway Engineering in Connecticut for modifications. This $51,000 option included the addition of twin-turbos which resulted in 345 horsepower. The first four twin-turbos used re-worked truck blocks but the remaining used the production Vette engine. A total of 123 Callaway coupes and 65 Callaway convertibles were produced.

1988 – The 1988 model year represented the 35th anniversary of America’s sports car. To celebrate, a special trim package was made available and 2,050 were sold. This special edition sported white paint with a black roof bow, white leather interior including the steering wheel, white painted wheels, and special badging inside and out. The option was only available on coupes.

Other new goodies for the 1988 model year included carpeted door sills, more durable carpet and improved air flow ventilation for coupes. A new exhaust was standard on coupes with the 3.07:1 rear axle ratio, providing five extra horsepower due to its less restrictive flow. The new muffler system was deemed too raucous for the roadster and the 2.59:1 rear axle ratio coupes and was not installed. Standard brake rotors and suspension was revised to perform better under hard braking. The Z51 and Z52 saw new design 17 x 9.5 inch wheels with P275/40ZR 17 tires. The Z51 option (only available on coupes) also included a finned power steering cooler, higher spring rates and big front brakes.

1989 – The biggest change to the Corvette this year was the edition of a ZF-sourced six-speed manual transmission. This would also be the last year of the of the horizontal dashboard. Although a matter of taste, we think this original dash is the more attractive.

Standard this year were the P275/40ZR17 tire and 17-inch wheel setup that had been previously part of the Z51 and Z52 packages in 1988. The Z52 option was ash-canned this year as well, and replaced with a new “Selective Ride and Handling System” (RPO FX3.) It was only available with the manual transmissions and cars equipped with the RPO Z51 “Performance Handling” package. The SRC (Selective Ride Control,) system offered three modes of driving: tour, sport and performance.

A new simpler folding top for the convertibles was introduced as well as newly designed sports seats that resembled the Michelin man. A fiberglass auxiliary top was available for the convertible for the first time since 1975. The sport seats were only available in cars optioned with Z51 because of weight and fuel economy concerns.

The end of the ’80s also began the gestation period for the Corvette ZR-1 “King of the Hill.” Eighty-four prototypes were built although the car was delayed until the 1990 model year.  When the smoke cleared, sales of Corvette were half of what they were for 1984 at 26,412.

1990 –  Corvette received a major interior update with new instrument cluster and interior trim. The new unit ditched the horizontal setup of previous cars with a semi-circle binnacle in front of the driver with airbag now standard equipment. An ABS-II anti-lock braking system was also standard across the board.

This year was also the debut of the legendary “King of the Hill” Corvette ZR-1, a ferocious beast that really caused a commotion around the world. The ZR-1 engine was a GM spec, Lotus-designed 32-valve, dual-overhead-cam, 350-cubic inch V8 built by Mercury Marine in Oklahoma. With 375 horsepower it’s tame by today’s standards, but was a truly a monster back in the day.

The ZR-1 also included new body styling from the B-pillar rearward with a wider rear bumper cover to house the massive 315/35ZR 17 rear tires. The FX3 Selective Ride Adjustment was a standard feature on ZR-1’s as well as the six-speed manual gearbox. The ZR-1 rear body styling included a convex rear with rectangular lights, the standard Corvette has a concave rear with round lights.

Chevrolet clocked out of 1990 with 26,412 Corvettes sold, 3049 built out as the ZR-1 model.

1991 – The Corvette received a very attractive exterior update for this year. The black rub strip surrounding the beltline was now body color, the front fascia was smoothed with wraparound side markers, and the ZR-1 tail with squared off taillights was standard across the range.

A RPO Z07 option included the Z51 suspension components and the FX3 adjustable ride options and provided an in-cockpit adjustable ride from stiff to very stiff. A power source was added for accessories like cell-phones and a float based oil pressure monitor. A new retained accessory feature allowed the windows and radio to work for a time after the ignition key was removed.

This was the last year for the L98 350 V8 motor. Chevy kept the Bowling Green plant barely breaking a sweat with 20,639 units sold, with 2044 ZR-1s.

MODEL YEARS 1992-1996 (LT1 ENGINE)

1992 – This was a big year for Chevrolet as it introduced the first rethink of it venerable small block V8, introduced this year as the LT1. The new engine produced 300 horsepower and 330 lb-ft of torque. Weighing in at 452 pounds, the LT1 is approximately 20 pounds heavier than the L98 that it replaced. The engine used a novel “reverse flow” cooling system that routed coolant to the heads first and then the block.

“Acceleration Slip Regulation” (ASR) was a new traction control system and improved weather stripping and extra insulation kept the cabin drier and quieter. On the ZR-1 badges were added above the gills on the front fenders. The instrument panel was updated including all black buttons and easier to read instrumentation. The power delay feature added the passenger door to cut power to accessories after the key was removed.

The one-millionth Corvette rolled off the assembly line in 1992 as well. Chevrolet cranked out 20,479 with just 502 ZR-1s for 1992.

1993 – This was the 40th anniversary of the “Plastic Fantastic.” A special anniversary package was offered in Ruby Red paint and guts. The interior had embroidered headrests and badging on the hood, deck and side-gills. All leather seats across the lineup had the 40th anniversary badge on the headrest, the base black cloth seats did not.

ZR1The ZR-1 got a power boost this year jumping 15 horsepower from 385 to 405. Torque was also improved from 370 lb-ft to 385 lb-ft. This was attained through porting changes on the head and valvetrain, an electric EGR valve improving emissions, and four-bolt main bearing caps. A new passive entry system that unlocked the car when a special key fob was near the car was optional. A new polished wheel was standard and the tire and wheel sizes were reduced by one inch all around on all 1993 Vettes except ZR-1. Production was 22,048 with 448 ZR-1s.

1994 – This year saw minor alterations. The LT1 remained at 300 horsepower although the addition of a sequential fuel injection system improved idle, drivability and emissions by firing the injectors in sequence with the firing order.

The standard four-speed automatic transmission was updated to include electronic controls to improve shift performance. All seating was offered in leather only, the rear window in the convertible was changed from plastic to glass and the air conditioning system now used R-134A refrigerant, which pacified tree huggers everywhere.

September 2, 1994 marked the opening of the national Corvette Museum in Bowling Green, Kentucky as well. Chevy delivered 23,330 including 448 ZR-1s.

1995 – This was the last year for the ZR-1. By the end of the 1995 model year, 6939 ZR-1s were built. The roadster paced Indianapolis  this year and 527 funky, striped replicas were built in purple and white. Minor trim changes and a “Dark Purple Metallic” paint color was added as well.

Kentucky’s Bowling Green cranked out 20,742, including the the last 448 ZR-1s.

1996 – This was the end of the line for C4 and represented the final model with every update and tweak Chevy could muster. The best news was the 330 hp LT4 motor which was only available with the six-speed transmission. Two new options were created to fill the vacuum created by the dearly departed ZR-1, the Grand Sport and the Collector Edition. The Grand Sport included the LT4 engine and an Admiral Blue paint job with white stripes, and red hash marks on the front fender. It also included black five-spoke wheels.

The collector edition included an exclusive Sebring Silver paint, special badging and silver five-spoke wheels. It included the LT1 engine with the automatic transmission; the LT4 and manual transmission were optional. A new optional “Real Time Damping” system measured travel at each wheel and adjusted suspension options electronically. The optional Z51 suspension was tuned for autocross and Gymkhana competition.

What Are These Cars Worth?

The collector car market fluctuates from year to year and is influenced by the economy and the whims of the hobby. The best way to ascertain what a C4 Corvette is worth is to find comparable cars for sale that are similar to a car you’re looking for. A keen buyer will scour Craigslist, Hemmings, AutoTrader, and other publications to see what cars are bringing. Auction houses like Barrett-Jackson and Mecum’s are good resources to monitor the fluctuation of value.

Joining a Corvette club could be a valuable resource as well as online forums and chat rooms. The National Corvette Restorers Society is also great resource too. As always, keep your eye on Corvette Online as well.

The Verdict?

When looking back on the C4 era, one thing becomes clear. They made over 350,000 of them! That alone has done nothing to add value to these cars. Also, the car got better as the production run wore on. A post-1992 model that is original and well cared for seems to be the best bang for the buck.

The real sleeper is the ZR-1, with 1990 models most plentiful. One thing is for certain, with prices hovering around $20K they are bound to go up in the future. The ZR1 owner base is well organized and can provide all the nuances of this King Kong Corvette. Next in line are the 1996 Grand Sport models with the LT4 motor. These are drop dead gorgeous and have all fixes and enhancements baked in.

Finally, the quality of any car is an important factor in determining value, but color and options are critical factors as well. Callaway Turbos, Convertibles, Pace Cars and Anniversary models come to mind here.

Documentation can really add value to the car as well. Brochures, bill of sale, factory owner’s manuals and maintenance receipts can substantiate originality and provenance. Original cars are also worth a premium as many ‘Vette aficionados stand by the old mantra, “they’re only original once.”

Ultimately, the goal is to take your time, exercise due diligence by researching online, talking to Corvette club members, or hiring an expert to suss out good cars from bad. Happy hunting!