If you've ever contemplated restoring a C4 Corvette and received a chilly reception from your family and friends, consider directing them to the Corvette C4 Guru Forum (www.c4guru.com). The site dedicates itself to the preservation of the '84-'96 Corvette, with an extensive tech library, videos, forums, RPO codes, data sheets, specs, and more.
Casey Webster, a 27-year-old maintenance technician from Sippy Downs, Queensland, is a moderator of the site and one of its online gurus. "I love Corvettes," he says. "I've been driving Vettes since I was first licensed. When I was 17, I worked almost 60 hours a week to get my first one, an '87 coupe. In the past nine years, I've pulled apart almost every single area of a C4, so I've got a fair amount of experience with them."
An L98 '87 Corvette was a great introduction into the hobby for Webster, but he knew he wanted a bigger slice of performance. That extra urgency debuted in the Corvette in '92, in the form of the Gen II LT1 engine. In 2001, he purchased an Arctic White '94 coupe that had immigrated to Australia after the end of the C4 era.
Like most of the 4,066 Arctic White Corvettes that rolled off the Bowling Green assembly line in '94, Webster's Corvette was equipped with an LT1 engine and a four-speed automatic transmission. Output was rated at 300 hp, an increase of 60 hp over the '87 model. The base price was $36,185.
"The '94 had a lot of work done on it, so I didn't have to worry about being the one that modified a perfect, original car. But it needed a lot of work, too, and I knew I could do all that work myself and save a lot of money," says Webster.
Because the paint was (surprisingly) factory original, Webster focused first upon the car's mechanicals. He commissioned a 4L60E trans rebuild from Adams Automatics of Caloundra, Queensland, and then corrected the C4's few existing flaws by repairing the pop-up headlight assembly and swapping the rubber suspension bushings for polyurethane units.
Next, Webster removed the interior trim and lathered the inner surfaces of the body shell with DynaMat Extreme sound-deadening material. He reinstalled the thrones-now resewn with black leather and accented with white welting and embroidery-and reused the original panels and carpet. He was saved the expense of a government mandated right-hand-drive conversion (required on all imported LHD cars fewer than 25 years old) because the Corvette had already been modified to RHD by a previous owner.
Webster's next step was to darken the sidemarker and taillights, after which he turned his talents to the engine compartment. He replaced the original water pump and heater core, citing "previous owner neglect" as the cause of their failure. He then spent several days performing diagnostic testing and data-logging, eventually tracing a hesitation problem to a blown head gasket. He removed the heads and sent them to Iain Woodward in Brisbane for CNC porting. At the same time, he sourced new gaskets from Don MacLeod of Maxx Wrench in Burlington, Colorado.
In reassembling the motor, Webster stayed with the stock displacement of 350 cubic inches, also retaining the LT1's cast-iron crank, powdered-metal connecting rods, and hypereutectic-aluminum pistons. The freshened aluminum heads were returned to him ready to rock, with Crane Gold 1.6-ratio rockers, Crane 99838 springs, 2.02/1.60 valves, and new factory pushrods. He installed a Crane hydraulic roller cam with 222/230-degree duration and 0.509/0.528-inch lift on a 112-degree lobe-separation angle. The compression ratio was bumped from 10.4:1 to 11.0:1.
The air-induction system features a GM air lid, a K&N filter, and a ported 48mm GM throttle body. An OptiSpark distributor ("It's an exceptionally good system and gets a lot of ridiculous unfair criticism," says Webster) directs spark down 8mm GM wires to NGK Iridium TR55IX plugs. Premium fuel flows from a 255-lph factory pump to 30 lb-hr Bosch injectors installed in a ported factory intake. Exhaust gases are evacuated through "tri-Y" long-tube headers with 1 3/4-inch primaries, 2-inch secondaries, 3-inch collectors, twin highflow stainless converters, Genie stainless mufflers, and 3-inch pipes.
Power moves from the crank to a 3,200- rpm lock-up torque converter, rearward to the bulletproof 4L60E, and then through a factory driveshaft to a 3.33-geared Dana 44 rear from an '89 six-speed Corvette. Webster also replaced the rear wheel bearings and the universal joints with Spicer products.
The Vette's ride and handling are meliorated with an RPO Code Z07 adjustable-suspension package employing a lowered "FHB" front spring sourced from a '91 coupe, a lowered "BMF" rear spring, and Koni adjustable shocks at all four corners. Braking comes from factory JL9 four-wheel discs. GM A-mold 17x9.5-inch wheels bolt to the hubs and are wrapped in Hankook Ventus Sport (front) and Federal SS 595 (rear) 275/40ZR17 rubber. Webster had the wheels powdercoated in white before fitting them to the car, but he kept the center covers in their stock silver color to add contrast to the nearly all-white exterior.
The last steps of the restoration involved brightening the engine area. Webster removed the factory valve covers and painted them blue. Braided stainless-steel lines were also added to protect the hoses from damage.
The verdict? Webster says his Corvette is a blast to drive, and the modified LT1 has gobs of power. Even though his earlier Vette had more "low-end punch," he says the '94 "pulls extremely hard from 3,000-6,000 rpm." The numbers back up these statements: The LT1 produces 413.7 hp at 4,800 rpm on an engine dyno, nearly 114 more than stock.
"They have both been great," Webster says of the two Corvettes. "The '87 was a factory-perfect example, and I didn't want to start changing it from that. It was a very reliable car. But the '94 is all power, and although it still looks pretty stock, it's a lot further from it than many people would ever be able to tell. I wouldn't say I like either one better than the other. I love them both, although the '94 is now a far better car than the '87 could've ever been."
Given the 168,000 miles on its odometer, it's hard to believe the Corvette retains its original paint and still looks factory pristine. Webster attributes it to the use of Australia's Bowden's Own car-care products. Whatever the reason, his hard work and attention to detail have paid off with some serious show-car accolades. The car took Second Place at the 2005 Corvette Classic at Southbank Parklands in Brisbane, followed by First Place at the show in 2006 and another Second in 2007.
As much as he enjoys shows, going fast in his Corvette is even more entertaining to Webster. "On my way home from work one night I had guy following me in a modified Nissan 200SX Turbo," he tells us. "The road was two lanes, and I was cruising along, thinking how mature he was to be just cruising along, too, when he suddenly sped past me out of nowhere. Knowing there was a set of traffic lights coming up, I was hoping he would get stopped on a red, and as luck would have it, he did.
"As he sat there revving his rice-burner, I chuckled to myself and sat there calm, reached over and shut off the Acceleration Slip Regulation (ASR), and waited for the green light. I was quietly confident as the light went green, and if the road wasn't dead straight, he wouldn't have known which way I'd gone. I must've put three car lengths on him by the time I was at 100 kph [62 mph]. Shortly after that, I was back in 'cruise home mode,' and he flew past me as if he won!"
Yes, Webster, it looks like you really are the winner. After all, you're the one with the Web site, your car is featured in VETTE, and although you're 6,350 statute miles from the Arctic Circle, driving is always a blast-an Arctic Blast that is.
|Heads||Ported LT1 aluminum|
|Camshaft||Crane Cams HR; 222/230-deg duration,|
0.509/0.528-in lift, 112-deg LSA
|Rocker Arms||Crane Cams Gold, 1.6-ratio|
|Intake Manifold||Ported stock|
|Throttle Body||Ported stock|
|Fuel Injectors||Bosch 36-lb/hr|
|Engine Management||Stock PCM|
|Exhaust System||Tri-Y long-tube headers (1 3/4-in primary, 2-in|
secondary, 3-in final collector), twin high-flow
converters, "straight through" Genie stainless
|Transmission||4L60E built by Adam's Automatics,|
|Torque Converter||3,200-rpm stall speed|
|Front Suspension||'91 Z07 FHB spring, Koni adjustable shocks|
|Rear Suspension||BMF rear spring, Koni adjustable shocks|
|Rear End||Dana 44 with 3.33 gear|
|Front Brakes||Stock discs|
|Rear Brakes||Stock discs|
|Wheels||White powdercoated GM A-mold, 17x 9.5-in|
(front and rear)
|Front Tires||Hankook Ventus Sport, 275/40ZR-17|
|Rear Tires||Federal SS 595, 275/40ZR-17|
|Best 60-ft Time||Unknown|
|Miles Driven Weekly||Over 300|