They're winning races and going quicker and faster each time out. That's what you heard about the Max Wedge cars and the 426 Hemi-powered Darts and Barracudas long ago. Now you're hearing it about Mopar's factory-built Challenger Drag Pak cars.

We spoke with people who are working on, racing, and winning with them to find out more about Ma Mopar's latest factory race car.

Larry Griffith, co-author of the Authenticity Guide to the '09 Challenger Drag Pak cars, says he's now ready to update his. "What we'll do is go back, and do a little more detail [we need] to make one of those engines live, and work with all of the do's and don'ts," he says.

That work of Griffith and his partner, Larry Pontnack, led to one of their Drag Pak Challengers running a winning 9.59-second e.t. at 138.2 mph at Cordova Dragway Park in late November. "We know we can make it run 9.40s," says Pontnack of their cars' potential. "There's no doubt in my mind that we can run 9.40s."

One place it may do that is at Gainesville Raceway, at the Tire Kingdom Gatornationals. "That's the plan right now," says Griffith. "One of our cars will run at Gainesville."

The one they take there will benefit from what they learned about the factory LY-Body race cars, along with their own speed secrets. "We can give you a lot of that," Griffith adds, "but for a lot of the engine and little parts, we're going to [work] with Arrington Performance."

Griffith and Pontnack run engines built by Arrington Performance, and the engine builder there who specializes in Drag Pak engines, Danny Glad, says their 6.1 Hemi can make as much as 640 reliable horsepower. "We've had really good luck with those engines," says Danny. "It's hard to believe that you can run a Stock Eliminator engine with that displacement and make 640 horsepower. It really amazes me how those engines can make that kind of power."

And they're doing it within NHRA's rules for Stock classes. "You have to run the stock main caps and the stock block," Danny adds, "and you have to run a stock crankshaft, too."

That's where Danny's skills as an engine builder (whose experience includes building engines for Alan Kulwicki's NACAR Winston Cup team during their 1992 championship season) comes in. "Basically, what you're doing is blueprinting it," he says. "They give you a .015-inch tolerance on the stroke, so you want to carry that out to the max—just shy a couple thousandths for error in measurement in the tech line."

Danny says that their race engines are good for about 60 runs before a rebuild is needed, plus there's no problem getting parts for them. "All the major manufacturers have parts," he says. "You can run aftermarket rods, like a K1 or a Manley; you can run an aftermarket piston, but it has to be approved with an NHRA part number on it. JE Pistons has one, and Mahle has one."

All that reliable power needs a chassis that can turn it into win-light-lighting e.t.'s. That's where another specialist at Arrington, Jason Hensley, comes in.

According to Jason, the lightweight Challengers needed to go on a diet. "The biggest problem with them, when you get them, is the weight distribution," he says. "They're so front-heavy that they're really hard to get enough weight out of the car, so that you can put ballast in the rear to get the weight distribution to where it needs to be."

One trick: Swap the spindles. "They come with the SRT8 front spindles," Jason says. "The R/T spindles are a couple pounds lighter a side, so we get a set of R/T spindles and make those work."