Dream jobs. They can mean a lot of things to a lot of people. For motorheads, being professionally employed in the motorsports business would be a real kick. Living that dream is Jeff Guenther, who earns his paycheck in Huntersville, North Carolina, the heart of Nextel Cup racing, as an engine assembler for Joe Gibbs Racing. When he isn't spinning wrenches on high-rpm Brand X mills for the NFL coach, he's got this little Barracuda he plays with.
When you work as an engine...
When you work as an engine assembler for a NASCAR team, making over 500 horsepower from a .030-inch overbored 340 seems easy.
"I have always liked the '68 Super Stock Barracudas, but I couldn't afford to buy one," says the 41-year-old. "My goal was to make the car a restomod with a Super Stock feel to it."
After buying the car in 1994 for $2,500 and beginning the work on it in 2006, it would be ten years before it was finished. Them NASCAR boys keep guys like Jeff real busy. A long time association with the Mopar breed runs through the Guenther family. Jeff's uncle Kip was the "Guenther" on Ed Miller's championship-winning Plymouth back in 1967.
Jeff, of course, designed and assembled the engine in the Formula S fish, starting out with a '70-era block. But he also called on some of his buddies in the NASCAR and drag racing world, notably Pro Stock driver Jason Line, who pulled an actual 502 hp off the end of the crankshaft on this mill on the DTS dyno at Ken Black's KB Racing. Oh, we forgot to mention, other than a .030-inch cleanup, this is a stock displacement 340!
Taking a closer look, Jeff explained that Eric Maij at KB Racing (where Line works with World Champ Greg Anderson) extensively massaged the OE forged Chrysler crankshaft, pulling 500 grams off the counterweights for a true bob weight of just 1,780 grams; that 500 ponies came up at a buzzing but stable 6,800 rpm. The reciprocating pieces include JE pistons set right at a zero deck height in the line-honed-and-decked block, NASCAR-type Manley rods, and ARP bolts, all of which Eric balanced. A Comp mechanical roller cam specs out at .236 degrees on intake and .247 degrees on the exhaust at .050 inch went into the middle of the short-block. The rest of the specs are on a "need to know" basis, and apparently we don't need to know.
Next, Todd Ames at KB got tagged for the heads, a set of Edelbrock aluminum units that were thoroughly ported and then flow benched. Hardware for the valvetrain included Crane 1.6 ratio roller rockers and 5/16-inch pushrods, Comp Cams retainers and dual valvesprings, and Ferrea stainless valves. Mancini Racing came up with the timing outfit, and a six-quart oil pan rounds it out.
Custom stainless headers fit...
Custom stainless headers fit like a glove. There's a lot of bends, but they fit.
For induction, a Mopar single-plane intake ported by Joe Gibbs Racing intake specialist Rick Gurr matched with a Willy's-prepped 750 carburetor tops it off. The headers and exhaust are a work of art; NASCAR header builder Pro-Fabrication did that in 1.75- and 1.875-inch stainless steel tubing, and it looks like some sort of post-apocalyptic tuba; they are one-of-a-kind as well. The battery was moved to the trunk, while ignition chores are handled by MSD, Champion, and Delphi-Packard pieces.
The rest of the driveline consists of the Tremec TKO 600 five-speed stirred by a shortened floor-mounted Pistol Grip-style Keisler handle and an 8 3/4 rear with 3.91 gears.
However, Jeff also knows enough about stock cars that this one would benefit from some chassis tune-up as well, starting with Calvert bars in the rear and Edelbrock IAS shocks in all four corners. A Firm Feel steering box was added, and BF Goodrich T/A G-Force tires were selected to keep the 'Cuda stuck to the pavement. The final touch was a set of wide American Racing Torque Thrust II wheels for the retromod look.
They went to Aiken, South Carolina, where John Brew took it down to the basics, replaced the rot, and then applied three coats of PPG Global basecoat/clearcoat black. The final touch was the interior, where Corbeau front seats and a custom dash fabricated by Gibbs shop foreman Paul Charcut was added. Auto Meter gauges show what's going on under the hood, but the rest of the interior is still stock, with the OEM steering wheel restored back to original.
Jeff has spent over a decade in the world of NASCAR, and his wife Cynthia and daughters Emily and Lily were on hand as he wheeled the car around Road Atlanta during the 2007 YearOne Experience. He also thanks his racing family for what they did to make the 'Cuda a standout project.
"I have worked in NASCAR for 15 years," he says in conclusion. "And I have been blessed to work with the people at Joe Gibbs, KB Racing, and Pro-Fabrication, all of whom are some of the most talented people in the world at what they do."
'67 Plymouth Barracuda Jeff and Cynthia Guenther, Kannapolis, NC
Engine: The stock 340 was rated at 275 ponies from the factory. To almost double that, Jeff used his connections in the NASCAR world, plus his own assembly talent. KB Racing's Eric Maij lightened and balanced the reciprocating assembly; we imagine you could spin it with one finger once these guys were done tweaking it. A static compression ratio of 10.5 was achieved with the piston flush at deck height. JE sportsman pistons and wristpins, Manley NASCAR rods, and ARP hardware round it out. A Comp Cams mechanic roller is now in the center of the block. Todd Ames (also of KB Racing) reworked a pair of Edelbrock heads, spanned by a Mopar single-plane intake and a Holley-style carburetor by Willys. Pro-Fabrication did the one-of-a-kind headers.
Horsepower and Performance: Over at KB Racing before the install, Pro Stock driver Jason Line pulled the handle to get 502 horses (at 6,800 rpm) and 445 ft-lb torque (at 5,200 rpm) on the dyno.
Transmission: Five beats four-a Tremec TKO 600 with five gears is under a custom tunnel fabricated by Tom Welsh at Autocrafters.
Differential: The 8 3/4 banjo-type Sure Grip rear with a 3.91 Richmond gear and a set of Moser axles.
Suspension: Edelbrock was called on for their new IAS shocks; if these NASCAR guys are usin' them, they're probably pretty good! A Firm Feel steering box and rear-mounted Calvert bars get a grip on the rest of it.
Brakes: Master Power fronts and Wilwood rears put discs on all four corners.
Wheels: 17-inch moderns here-American Racing Torque Thrust II with 7-inch and 8-inch widths, respectively.
Rubber: Fish flying is handled by wide BF Goodrich T/A G-Force tires, 245/45/17 fronts and 255/50/17 rear. Only the lack of a rollcage and harnesses kept it off the road course Hot Laps at the Year One event.
Body: The sanitary bodywork was courtesy of John Brew of Aiken, SC.
Paint: Thanks to Brew, three coats of PPG basecoat /clearcoat black are on the car. If you've ever sprayed black, you can appreciate what John accomplished.
Interior: Still somewhat stock, the steering wheel was restored, but Jeff added a dash layout custom-fabbed by pal Paul Charcut at Joe Gibbs' shop; Auto Meter gauges are in place. Carbeau front seats plus a Keisler shortened pistol grip round it out.
Best Performance: We don't know, but it even looks good standing still!
"Mopars have been in my family for 40 years. My uncles Kip and Mike Guenther both raced; Kip was on the '67 Super Stock World Championship team." -Jeff Guenther