As rain poured down onto the National Corvette Museum parking lot, the rumble of a small-block Chevy cut the air. Suddenly a low-slung silver C4 drove into view. In spite of the weather, a crowd gathered around to check out this new visitor. Owner Keith Alexander climbed out, warmly greeted the throng, and proceeded to show off his custom creation, a 76,000-mile '96 Corvette built over the course of four years.
Fourth-generation Corvettes are the best performance bargains available in the hobby, with well-designed suspension components and strong chassis capable of handling lots of horsepower. Alexander's car is a good example of what can be wrung out of a C4, but it was just one of the many '84-'96 Vettes that made the trek to the annual Gathering.
Spotting special C4s at this event is a regular occurrence, and with good reason. A total of 358,179 units were built during that generation's 13-year model run, the second longest in Corvette history. (The '68-'82 cars beat the C4 run by two years.) While you can still find many C4 bargains, low-mileage ZR-1s, Grand Sports, and Pace Cars continue to command a premium.
The C4 raised the Corvette performance bar and set many records during its production cycle. These include the Callaway Sledgehammer's 254.6-mph top-speed run in 1988, as well as Morrison Motorsports' toppling of a 50-year-old speed record at Fort Stockton, Texas, two years later. The Morrison team averaged 175.885 mph in a preproduction ZR-1 over the course of 24 hours. This historically significant car is on permanent display at the NCM.
The weather kept the crowds down, but those who braved the rain were treated to a smorgasbord of historic fourth-generation Corvettes. One of our favorites was a stunning Nassau Blue Metallic ZR-1 development mule (EX 5023). During the ZR-1's development, Team Corvette constructed many prototypes for testing and evaluation. Most were destroyed when testing was completed, but EX 5023 got a stay of execution thanks to a transatlantic interpretational oversight. It seems the term "destroy" meant something totally different to the Englishmen at Lotus, who, instead of shredding their ZR-1 prototypes, merely crushed them. These crushed remains were later discovered among the weeds in an English salvage yard. They were purchased and resold to private buyers, and today many are being restored to their former glory.
EX 5023 is one of these cars, and it is a significant piece of Corvette history. As the accompanying junkyard-photo montage attests, the job of bringing this car back to life has required considerable effort. It's still a work in progress, but the job is almost complete. The owner displayed the original buildsheet that shows how the ZR-1 parts were added during the car's construction in 1987.
A second ZR-1 prototype was also on display. This yellow '86 Corvette is the only surviving test car from a fleet of 21 development vehicles sent to Lotus that year. The car was fitted with an early "Phase 1" LT5 prototype engine and was on loan from its British owner.
Numerous seminars were conducted at the Gathering, covering a variety of C4-related topics. These included how to tune your C4/ZR-1, swapping a C4 transmission, and information about various C4 exhaust options. NCM Hall of Fame member Gordon Killebrew, meanwhile, conducted his popular Gordon's Drive Through Troubleshooting seminar. Attendees always find these training sessions to be very enlightening. A People's/Celebrity Choice car show was held on Friday, and Gil and Betty Bockelman's beautiful '96 Grand Sport took top honors.
In addition to the panoply of C4s on display, the Bowling Green Assembly plant brought a surprise visitor to the event: a '12 Velocity Yellow ZR1, fresh off the assembly line and equipped with the new Michelin Pilot Sport Cup tires and revised close-ratio tranny. It's rumored that this car was later sent to the Nürburgring in Germany, where it lapped the 12-plus mile course in 7:19.6 seconds. (See "Lords of the 'Ring" in last month's issue.)
If C4s are your favorite generation, we recommend checking out the 2012 C4 Gathering. It's an entertaining and informative way to pay tribute to the car that brought modern technology to the Corvette platform.

01 Kevin Alexander has spent...

01 Kevin Alexander has spent four years turning his ’96 Collector Edition into a real barnburner. This street-driven ride is scheduled to have twin turbos added to its already head-and-cammed LT1 in the near future.

02 The interior of Alexander’s...

02 The interior of Alexander’s C4 is all business. It features a full rollcage, a custom dash, racing seats, and full instrumentation.

03 In spite of the rain,...

03 In spite of the rain, hundreds fourth-gen owners brought their cars to the NCM’s annual C4 Gathering.

04 Matukas Motorsports back-halved...

04 Matukas Motorsports back-halved Alexander’s car and built a new frame to accommodate a Ford 9-inch axle with a four-link suspension. The C4 sits on 18x10 front and 18x12 rear Fikse wheels wearing sticky BFGoodrich rubber.

05 Gordon Killebrew (right)...

05 Gordon Killebrew (right) is an expert on C4 electrical systems and a member of the NCM Hall of Fame. Here, he troubleshoots a broken headlight motor on an ’86.

06 One of the first-built...

06 One of the first-built ’12 ZR1s was also brought to the Gathering for all to see. It’s rumored that after the event, this car set a new lap record (7:19) at the Nürburgring in Germany.

07 The owner of this white...

07 The owner of this white ZR-1 painted his engine to match the car’s outside color. The combination makes quite an impression when the hood is opened.

08 This ’86 is autocrossed...

08 This ’86 is autocrossed on the weekends and was driven to the Gathering from Michigan. The car’s owner is shown here participating in Killebrew’s C4 troubleshooting class.

09 In 1985, the Corvette...

09 In 1985, the Corvette engineering team sent 21 test cars to Lotus Engineering in England. Once testing was completed

10 The car features an early...

10 The car features an early “Phase 1” LT5. Notice how different this engine looks compared with the final production version.

11 Only 1,000 Grand Sports...

11 Only 1,000 Grand Sports (RPO Z16) were produced during the ’96 model year, and each one carries a GS-specific VIN number. Bowling Green built 190 convertibles and 810 coupes, including these three well-preserved examples.

12 This placard reads, in...

12 This placard reads, in part, “EX5023 was the certification vehicle for engine calibration. GM ordered the car to be scrapped in England.” Instead of shredding the car, as was GM’s practice, the English junkyard used a front-end loader to crush it. Many original parts were salvaged, and the car’s present owner used a donor vehicle to aid in the rebuilding process.

13 Another “junkyard” English...

13 Another “junkyard” English find is this ’87 prototype ZR-1. EX 5023 was built on April 29, 1987, for Jim Ingles at the CPC Group Engineering center in Milford, Michigan. It was sent to England for testing and later crushed. It is now in the process of being restored.

14 EX 5023 is fitted with...

14 EX 5023 is fitted with a Phase 2 LT5, which is much closer in appearance to the production ZR-1 engine.

15 This is a copy of the...

15 This is a copy of the original build sheet for the EX 5023 prototype. Notice the many upgrades that had been penciled onto the sheet. These include the LT5 engine, six-speed transmission, 11-inch rear wheels, larger alternator, and 3.54 rear axle.

16 Roc Linkov, Events manager...

16 Roc Linkov, Events manager for the NCM, presents Gil and Betty Bockelman with the Best in Show award. The Bockelmans entered their '96 Grand Sport (No. 798) in the show after driving up from Missouri.