Being a well-educated Mopar man, Matt knew that the Sebring Plus was the ideal candidate for his project. Matt says the Sebring Plus was what you got back in the day if you wanted to pull a fast one on the insurance company. They looked just like a GTX, but with a 318 or a 400 instead of a 440. "The one I bought was a 318 car that a kid inherited from his dad, and wanted to sell in order to buy a new Mustang. The paint, bumpers, trim, and interior on this car were all perfect," he says. "The only rust were two dime-sized spots behind the rear wheels. Since most of the 318 cars were equipped with A/C, it meant that I didn't have to track down a dash with A/C vents in order to install an aftermarket system. Trim pieces and things like wiper arms and grilles are incredibly difficult to find on these cars."
After repairing the small rust spots, the GTX was disassembled and media-blasted down to bare metal. The chassis was then placed on a jig to ensure everything was square, and then stiffened up with U.S. Car Tool subframe connectors, torque boxes, a shock tower brace, and a radiator core support brace. "Even though B-Bodies are very stiff to begin with, I always insist on matching a car's rigidity to the torque coming from the motor. You don't want to put this kind of money into a car just to twist it up," he says. With a stiff foundation in place, the GTX was fitted with an RMS K-member up front and a four-link out back. AFCO double-adjustable coilovers, RMS tubular control arms, and Wilwood 13-inch brakes with six-piston calipers peek out from behind the spokes of the Wheel Vintiques Magnum 500 rollers at each corner. To finish off the body and chassis transformation, Matt sprayed the car in PPG Rosa Corsa Red paint.
Part of what turned Matt's Hemi 'Cuda into a lumbering giant on the road course was the big, heavy elephant motor underhood. To avoid that same mistake this go-around, he installed a lighter, late-model Hemi into the GTX. It started life as a Mopar Performance 392 crate motor, but has been bored to 4.090 inches and fitted with a Callies 4.050-inch forged crank. It sweeps the 10.0:1 Diamond pistons and Eagle steel rods up and down the bore for a total of-surprise, surprise-426 ci. Since driveability is paramount in Matt's street machine builds, he retained the 235/235-at-.050 hydraulic roller cam that came with the 392 crate. The stock heads were ported to flow 330 cfm, and they're fed by an XV Motorsports single-plane intake manifold converted to EFI, and a Holley four-barrel throttle body. A testament to the cylinder heads' outstanding airflow, the motor puts out 618 hp and 585 lb-ft of torque despite a modestly sized camshaft. Bolted behind the new-age Hemi is a Keisler-modified GM 4L60E transmission with paddle shifters, which sends torque to a Chrysler 8 3/4-inch rearend with 3.21:1 gears.
Considering that the GTX was specifically built to do the tango with high-dollar exotics on the road course, the big question is how well it performs in the heat of competition. "The back end stays planted, and it sticks very nicely, but you can still drift it just a hair if you want. This car is a beast on the road course, and I have no problem putting Z06 Corvettes in my rearview mirror," Matt says. Performance-wise, the GTX has come close to achieving his stringent standards, but to Matt, that's not enough. Supreme comfort can't come second to stunning performance, and that means he can't have that Gulf Coast heat and humidity sweating down on his parade. After all, this is a man who loves his A/C, and fortunately, the GTX delivers in every arena. "You couldn't get air conditioning with an old-school Hemi, and A/C wasn't available with factory air grabber hoods, either. I want it all-A/C, an air grabber hood, and power everything-and the Gen III Hemi lets me have it all."