March 9, 2007
John Stamper's clean, '90 LX notchback resembles so many other street-going 'Stangs out there. But instead of being a 12-second bolt-on car, this one packs an estimated 700-plus-horsepower surprise under the hood and predicted 9-second elapsed times. Once the blower passes 15 psi and the engine rips past 5,000 rpm, all hell breaks loose.

John Stamper has the right idea about cars. Not concerned with class legislation, he's been content to construct the 5.0 Mustang he wants to build: simple, powerful, and respected. In many ways, the car tells us more about the man who built it than he would ever tell you about himself. In the end, John's goal was simple-build a 5.0 Mustang that's a lot of fun to drive.

With that mature view of what a performance car is all about, you might guess John is experienced about life, and you'd be right. The now 62-year-young is a retired sergeant major from the U.S. Army who was a physician's assistant helping to defend our country until his retirement in 1987. He's always been into hot street cars-his first was a '55 Fairlane with the Thunderbird 312 V-8 option. He followed that up with a '69 Torino that packed the Ford 428 Super Cobra Jet, Ram Air, and a C6 transmission.

After leaving the Army, John turned his focus to the 5.0 Mustang, which at that time was starting to take over the streets of America. Looking for the next big thing in Ford muscle, the 5.0 Mustang was the obvious choice. John bought his notchback and began modifying it with the disciplined planning and execution befitting his military background. In 1995, John opened his own performance shop, Super Chargers Plus [(317) 440-2314] in Indianapolis, realizing that many people could benefit from his experience and skills.

Starting with the exterior of his own car, John didn't waste his money on looks. Nope-this is a down-to-business sort of car for an all-business owner. The Cervini's hood is a great mod, as it dumps some of the front weight and adds style. Other than the lightweight Weld rims, everything is as Detroit designed it or "a subtle little lady going down the street," as John describes the look.

Inside the '90 notch, you'll find stock seating with Auto Meter gauges and a custom switch panel in place of the radio controls. Where a passenger seat once took up residence, John had his brother fab up a trick reservoir out of diamond-plate aluminum to feed ice-cold water to the Vortech Power Cooler. The shifter is attached to a Dynamic C4 automatic with a 3,800-stall that still keeps street driving a reality. The 8.8-inch rear holds 3.55 gears.

But it's no subtle lady when the throttle is cranked. John put together the motor in 1998, and through the years he's bolted several good pieces on the 306. We captured it on film in the summer of 2004. Featuring a Vortech T-Trim, a Vortech Power Cooler, Trick Flow Twisted Wedge heads, and little else, the motor was kicking out more than 600 hp before John shut it down due to lack of fuel during a chassis-dyno test session. Then he popped in some 50-pounders that replaced the overwhelmed 36-lb/hr injectors and added a second Vortech T-Rex fuel pump. To be honest, he's probably still on the dangerous side when the thing hits 26-plus-pounds of boost, but John quickly admits the current fuel system isn't his last.

He chose a proven performer with an F303 Ford camshaft, which was designed to work with supercharged combinations just like John's. Sure, there are dozens of custom blower-specific camshafts to choose from now, but John isn't into giving away his street manners for the sake of some horsepower. We have to say, though, you could probably find another 100 hp in this combo if you started testing camshafts.

"In 1998, it was one of the better cams," John tells us regarding the F cam. "I just built this motor for fun. It had to be street friendly. The F303 doesn't have a ton of lobe, and you can make it idle nicely. I'll tell you, it has a ton of top-end power."

John's suspension is also a study in efficiency and bang-for-the-buck. Koni adjustable struts and shocks make up the bulk of the mods. He replaced the upper and lower control arms with pieces from South Side Machine and Metco, and the front sway bar is long gone. Also helping weight transfer is a set of Moroso Trick springs that John describes as difficult to install but tremendous at lifting the front of the car while squatting the rear.