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1981 Ford Mustang - The Foxinator

Don't Underestimate Kevin Kenley's '81 Mustang.

By , Photography by

Kevin found nearly everything he needed for the swap on eBay, and after three trips to the Bureau of Automotive Repair referee station, his car passed. He was given a plaque to attach to his doorsill validating his swap, and his wheezy old pony now terrorizes the streets and dragstrip with nearly three times the power it could have dreamed of making 30 years ago.

Tech Notes
Who: Kevin Kenley
What: '81 Ford Mustang
Where: Rancho Cucamonga, California. Cucamonga can be translated to either sandy place or place of the villages where water comes out. Apparently, they get runoff water from the San Gabriel Mountains there.

Engine: Here's what we love about these engines-the entire long-block is stock. The Terminators have a forged reciprocating assembly, but the block is the same cast-iron 3.552-inch-bore piece you'll find in any run-of-the-mill, two-valve Mustang, Crown Victoria, or Town Car for that matter. (Spare us the nasty emails-we know the Cobra engines were cast without a knock sensor boss in the valley of the block to make room for the intercooler.

Otherwise, it's the same engine block.) The crank has a 3.543-inch stroke, adding up to 281 ci or 4.6 liters. The heads, cam, and valvetrain are stock Mustang Cobra. Kevin still has the stock iron exhaust manifolds. The key here is big airflow courtesy of the Kenne Bell supercharger. It physically delivers more air than the stock supercharger. At full song, or "death moan" as Kevin calls it, he will peg his boost gauge at 17 psi, and that contributes to a major jump in power from the stock configuration. To fit the mod motor, Kevin bought a tubular K-member from AJE Racing ( The company makes all kinds of engine swap stuff for Chevys, Fords, and Mopars.

Fuel: While the engine is mostly stock, the fuel system had to be modified to cope with the huge increase in air being ingested by those relatively small cylinders. Kevin upgraded to a pair of Focus fuel pumps, a Kenne Bell Boost-A-Pump, and FMS 60 lb/hr fuel injectors.

Transmission: Though Cobras have T56 six-speeds from the factory, Kevin found a killer deal on a used Viper T56 transmission. A Viper trans has the strongest internals of all OE applications. The input shaft and shifter had to be modified to fit his car.

Rearend: Some Fox-body owners switch to an independent rear suspension when doing Cobra engine swaps. Kevin is more concerned with performance at the dragstrip than the road course, so he stuck with a 8.8-inch solid rear axle-but it's an 8.8 with a 9-inch twist. He sent the housing to the guys at Currie, who welded on the big-bearing Torino axle flanges that accept 9-inch bearings and axles. The differential is a Detroit Locker with 3.73:1 gears. Ted Brunson at Bill Thompson Enterprises did the assembly, and Ed Moore built a steel driveshaft for Kevin after he snapped two aluminum ones.

Exhaust: Simple stuff here-a MAC after-cat system with an H-pipe.

Suspension: At the time the pictures were taken, Kevin's Fox was riding on stock front control arms with Del-a-lum bushings, MAC tubular upper rear arms, Maximum Motorsports Extreme Duty lower rear arms, Eibach springs, and Tokiko shocks. He's since swapped his stock springs back in, hoping the softer springs will help plant the rear on hard launches at the dragstrip.

Brakes: That's a Baer 12-inch system up front and an '04 Cobra set on the rear. The Cobra rotors had to be redrilled to fit the four-lug axles.

Wheels/Tires: The rubber is a set of Nitto 555s, sized 245/45R17 up front and 275/40R17 on the back. Because Kevin is planning to compete in our Engine Swap Drags, he's got a pair of Mickey Thompson drag radials on the way.

Paint/Body: The car was actually painted eight years ago, way before Kevin got the notion to do an engine swap, so it has a few scratches from sitting. He wants to have it painted again but can't afford it yet: He has a wife and five kids and they're all just moving into a new house. Don't worry Kev, we like the car the way it is.

Interior: Kevin is especially proud of the work he's done to the interior. He replaced the '81 dash with one from an '86 Mustang filled with VDO Millennium gauges rather than the stock stuff. The center console is made from the best parts of '86 and '96 consoles grafted together. He threw in a cupholder from a '98 Mustang for good measure. The seats are from an '89 Saleen Mustang, and he fitted the Cobra pedals to his '86 dash. He also grabbed the carpet and sunvisors from an '04 Cobra and one of those autodimming rearview mirrors from a Suburban-"the only Chevy part on the car," Kevin jokes. He mounted HVAC control switches from a '96 Mustang to his hybrid console.

The Swap: Once Kevin had the AJE crossmember in place, physically getting the engine in the car was easy. Wiring up everything was the hard part. Kevin bought the Ford factory service manuals and a DVD of the Cobra's wiring schematic. He took apart his stock '81 harness and the donor '04 harness, removed the components he didn't need, and created a new harness to fit his car. In the process, he upgraded the fusible links from the old car to the better relays and junction boxes of the new car. "In all, I have between 200 and 300 splices and connections to get the two looms integrated together," he tells us. Once the engine was installed and wired up, he had it tuned by Ricardo Topete at GTR Performance. It made 434 hp to the wheels with the stock supercharger. After dropping on the Kenne Bell, he took it to Adam Montague of ST Motorsports for a new tune-up. With the twin-screw blower, his safe tune makes 543 hp and 485 lb-ft at the wheels. On 100-octane gasoline, Kevin can dial it up to 607 hp and 545 lb-ft. His best pass so far is an 11.2 at 124 mph. Traction is his biggest problem now. He promised to keep us updated once he makes it back to the track with the softer springs and drag radials.

Thanks: Kevin has a long list of people he wants to thank for helping him get his car back on the road. First up is his wife, Margaret, for "putting up with all the time spent on, in, and under the car while she was taking care of the kids." In addition, he wants to thank friends Mark Sanchez; Damon Howard, who helped with garage space; Randy Moruzzi, who did the plastic welding on his dash; John Mihovetz of Accufab, who gave him a price break on parts; and his sister, Kerry, who donated her garage for a couple of years.

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