It takes quite a car to catch a magazine editor’s eye, but this one did just that at 2010’s Corvettes at Carlisle. But unlike many of the restored and modified Vettes that were on hand, much of this one’s conversion was done by its owner—in his garage.
John Callahan bought this ’07 coupe new at Kerbeck’s in Atlantic City, New Jersey, in September 2006, but it wasn’t his first Corvette, or even the first in his family. He’d owned an ’87 and a ’95 before this one, and his brother-in-law, Jim Uriah, had a ’99 fixed-roof coupe with a ProCharger and CCW wheels.
That fixed-roof C5 got Callahan thinking about his C6—and, eventually, upgrading it. “It started out as me just wanting the rear wide-body kit,” he says. “The more I got into it, the more it happened that way.” And the more the upgrades came to mind.
His first one: a supercharger. “The reason I did it was because my brother-in-law had his,” says Callahan. “When he got his ’99, the first thing he did was put a supercharger on it. That’s why I’d always wanted one—because I’d seen what his car did.”
Unlike the ProCharger on Uriah’s ’99, this Vette received a polished Paxton Novi 1200 with an East Coast Supercharging methanol kit. On top of his otherwise-stock ’07 LS2, the Novi bumps output up to 711.4 rwhp and 646 lb-ft of torque.
To complement his polished power adder, Callahan dressed up the engine bay with chrome replacements for the coil, fuse box, master cylinder, and power-steering-fluid reservoirs, as well as the dipstick.
Under the hood, a Paxton Novi...
Under the hood, a Paxton Novi 1200 supercharger shares space with a full battery of complementary chrome bits.
The only other change he made to the powertrain was a B&M shifter replacing the stock one. Other than that, it has the same six-speed MN6 transaxle and 3.42 final-drive gearing that went in at Bowling Green.
The exterior of Callahan’s ’07 is another matter. “I just like the look of the ZR1,” he says, which was reason enough to make his ’07 look like one.
Instead of trusting the conversion work to an outside shop, Callahan chose one closer to home. “I did it in my garage,” he says of the changeover, ably assisted by his local painter, Jeff Bong. “I’d take one piece to Jeff and he’d paint it, then I’d bring it back home and take another one to Jeff, and he’d paint that.”
After Bong did the paintwork, Callahan installed the ZR1 pieces himself. “Most people don’t believe I did that in my garage, because I replaced every single panel on the car except for the doors, rockers, and hatch,” he says, adding that those parts that stayed on were painted at Bong’s shop. “Everything else is a GM carbon-fiber part for the ZR1.
Paired with an ECS methanol-injection...
Paired with an ECS methanol-injection system, the blower bumps output to 711 hp and 646 lb-ft of torque.
Inside, along with the B&M shifter, Callahan added a Pioneer CD/DVD sound and video system, plus carbon-fiber accent pieces all around the cockpit. But Callahan has some future plans for inside.“I’m going to do a Down South Vettes interior,” he says. “I’m planning on doing the steering wheel and the seats.
With an engine whose output has been boosted from less than 400 horses to more than 700 (711.4, per the dyno), you can guess what this car is like to drive.
“It’s very fast!” says Callahan with a big laugh. “I went from having 383 horsepower to 711. It took a lot of getting used to.” Even with all that power on tap, Callahan says that his ’07 still runs like a stock LS2-powered Corvette while highway cruising.
Callahan’s best time in the quarter-mile is 11.96 seconds at 119 mph, which he says was run with just a tune and headers. He hasn’t had it down the track since the blower install.
John Callahan added the ZR1’s...
John Callahan added the ZR1’s looks to his C6, thanks to factory GM carbon-fiber ZR1 body panels.
“That’s because it turned out so good that I’m scared I’ll break something,” he says. “I really don’t want to beat it now.” Another reason: Having a car that quick takes the fun out of the track-day trips with his buddies who have stock (or close to it) Corvettes. (That, and needing to install a full rollcage if he runs a sub-11-second pass on many tracks.)
But that doesn’t mean he won’t air it out occasionally. “I’m going to run it someday, just to see what it can do, but I don’t know how soon,” Callahan says. “I know that I’m not going to be able to go all out. I have Drag Radials for it, but I don’t think that I’ll break anything with them on, because they’ll spin first.”
One place that Callahan took his Corvette was last year’s Corvettes at Carlisle show. That’s where Editor Heath saw it and made it his “Celebrity Choice” winner.
Not bad for a car inspired by a brother-in-law’s Corvette...and built in the owner’s garage!

Jeff Bong’s paintwork on the...

Jeff Bong’s paintwork on the ZR1 bits (as well as on the factory doors and hatch) is incredible.

Filling the fenderwells are...

Filling the fenderwells are 20-inch D2 Forged VS1s on Nitto Invos.

For now, a B&M shifter, a...

For now, a B&M shifter, a Pioneer audio/video system, and carbon-fiber accents make up the interior mods, but a Down South Vettes cabin makeover is in the works.
| Spec Sheet: ’07 Coupe |
| Owner | John Callahan; Allentown, Pennsylvania |
| Block | Stock LS2 aluminum |
| Displacement | 364 ci |
| Compression Ratio | 10.9:1 |
| Heads | Stock LS2 aluminum |
| Valves | Stock 2.00/1.55 |
| Camshaft | Stock hydraulic roller |
| Rocker Arms | Stock 1.7 ratio |
| Pistons | Stock hypereutectic |
| Crankshaft | Stock nodular iron |
| Rods | Stock cast |
| Intake Manifold | Ported stock |
| Power Adder | Paxton NOVI 1200 supercharger with ECS methanol kit, 13 psi boost (max) |
| Fuel Injectors | 60-lb/hr |
| Fuel Pump | Stock with Kenne Bell Boost-a-Pump |
| Ignition | Stock coil-on-plug |
| Exhaust System | 1 3/4-in American Racing headers, Billy Boat “Bullet” exhaust |
| Transmission | Stock six-speed manual |
| Clutch | Stock |
| Driveshaft | Stock |
| Suspension | Stock Z51 |
| Rearend | Stock with 3.42 gears |
| Brakes | Stock Z51 with nickel-plated rotors and red powdercoated calipers |
| Wheels | D2 Forged VS1 chrome; 20x10-in front, 20x12.5-in rear |
| Tires | Nitto Invo; 285/25ZR20 front, 345/25ZR10 rear |
| Fuel Octane | 93 |
| Weight | 3,300 lbs with driver |
| Best ET/MPH | 11.96 sec at 119 mph (NA) |
| Best 60-ft. Time | 1.70 sec |
| Current Mileage | About 20,000 |