Stiffen Your A- Or G-Body Frame With A Frame FX Kit From Hellwig

Despite all of their retro-cool points and the advent of the modern LS/LT engine swaps, classic General Motors A- and G-body vehicles have never been known for their stiffness or handling. While modern coilover suspension swaps, sway-bar upgrades, and multi-link conversions certainly help, the flex found within the vintage A- and G-Body frame remains a major Achilles heel for these vehicles… at least, until now.

Although adding various forms of support bracing to the unseen portions of a chassis has long been known to improve rigidity, being able to properly “box” a factory chassis requires an extensive amount of measuring, cutting, fitting, and welding. In order to alleviate the burden of producing these steel panels yourself, suspension specialist and founding SEMA member, Hellwig Products, has created a “weld-in” alternative for fans of A- and G-body vehicles.

A-body models produced from 1964-1972, include the Chevelle, Malibu, Monte Carlo, Cutlass, F85, LeMans, GTO, and Skylark. G-body vehicles made from 1978-1987, refer to the Regal, Century, Grand National, Malibu, Monte Carlo, Cutlass, and LeMans.

Hellwig Products branded its steel reinforcements as Frame FX Kits. Precision-cut from hunks of 10-gauge steel to provide uniform fitment and an OEM appearance, these weld-in upgrades are marketed as a product that will eliminate the “wobble” commonly associated with A- and G-Body cars.

Each weld-in Frame FX Kit features 14 pre-formed steel panels designed to fit in the weakest areas of each factory frame rail, thus giving GM enthusiasts the ability to retain their factory chassis and all of its stock mounting points.

Once installed, drivers will notice the Frame FX Kit’s added strength not only cuts down on wobble but improves both steering response and ride quality, as well. Regardless as to whether you’re considering swapping in a modern, high-performance powertrain, are planning on running larger wheels and tires, or are prepping for race season, the Frame FX Kit from Hellwig demands consideration.

With the increased stiffness our Frame FX Kits provide, you can instantly feel the effect it has on the handling, comfort, and performance of the overall driving experience. – Mike Hallmark

The Enemy Lies Within

So what’s the big issue with the average General Motors A- or G- Body vehicle frame? Looking to save some weight (and pinch a few pennies in the process), GM engineers designed these automobiles to sit atop what is commonly referred to as an open C-channel chassis.

Just a mere 3-inches wide at the top and bottom, this frame design did what it was supposed to, but made the chassis inherently weak when handling torsion, and only marginally better in regard to bending. Throw in the fact that the average A- or G-body vehicle has seen countless miles of use and abuse over the course of the past few decades, and you’ve got one fatigued frame in need of reinforcement.

The stock C-channel frame is inherently weak by design. Hellwig Products’ Frame FX Kits box this opening in to eliminate flex.

How Hellwig Fights Back

When we asked Mike Hallmark, marketing and international sales manager at Hellwig Products, about the reasoning behind the Frame FX Kit’s development, he had the following to say.

Doubling the width of the tension side of the framerail, and then closing-off the cavernous area found within the open chassis, is how Hellwig’s Frame FX Kit is able to dramatically increase torsional rigidity while providing superior resistance to flexing.

“Like all of our products, our Frame FX Kits were created to solve a problem. With the open-channel frames of the A- and G-body, we knew we had to come up with a simple solution to box and stiffen the chassis,” Hallmark says. “Our pre-bent, multi-piece steel frame boxing kits are a breeze to install, taking roughly 6 to 8 hours to fit and weld into place.”

Frame FX Kits are a no brainer upgrade for fans of the A- and G-body chassis, offering custom-reinforcement features while eliminating much of the guesswork and measuring.

Made from fourteen pre-cut, 10-gauge steel panels, the Frame FX Kit not only matches the thickness of the factory frame for a uniform finish, but it also focuses on reinforcing the weakest points of the chassis. However, in order to stiffen the factory chassis to a point where drivers could genuinely feel a significant improvement in handling and ride quality, Hellwig had to first think outside of the box.

“With the increased stiffness, you no longer have to worry about the frame twisting, creating fatigue and flex issues to the frame and body panels,” Hallmark says. “No more uneven body panel gaps or door misalignment.”

By going the extra mile and engineering a panel with an additional mount, Hellwig gave GM enthusiasts the ability to affix the floor pan to the chassis, thus adding an extra level of rigidity. In addition, brackets are created in such a way that the transmission crossmember has ample room for adjustment, therefore permitting a plethora of drivetrain configurations.

Converting the open C-channel frame into a boxed section also doubles the original frame width. Once welded-in, Hallmark tells us the reinforced frame becomes far more resistant to twisting and bending in extreme conditions, while improving steering feel, handling response, and ride quality.

Regardless as to whether you are into Pro Touring, drag racing, building low riders, or just want to beef-up a restoration project, the Frame FX Kit from Hellwig Products has you covered.

Race fans need not worry about these kits adding too much to their curb weight. Despite doubling-down on the width of the original frame, the Hellwig Frame FX A-body kit adds just a fuzz under 50 pounds to the weight of the vehicle, with the G-Body kit adding 59 pounds.

This significant increase in torsional rigidity and frame stiffness, coupled with superior steering response, ride quality, and handling, have made the Frame FX Kit a huge hit with racers. Hallmark is quick to point this out, saying, “Our Frame FX kit has been a game-changer in the Pro Touring market. Paired with our tubular front and rear sway bars helps transform these classics into corner-hugging performance machines.”

Each piece of 10-gauge, precision-cut steel in this 14-piece kit is designed to slide right into place. This reduces the need for extensive grinding and guarantees each Frame FX Kit will match-up with the stock chassis in OEM widths.

Installation Is A Snap

Despite this kit being a weld-in upgrade, Hellwig went through great pains to make installation as painless as possible. Every Hellwig Frame FX Kit comes in a two-piece design to cut down on the need for custom fabrication, with only minor grinding required to fit frame-dimension variances from the factory.

“We’ve had reports of customers welding our kits in place by simply lifting the body 6 to 8-inches off of the frame. Of course, we recommend giving yourself more room,” Hallmark tells us. “[However] this just goes to show how Hellwig has taken the tedious and time-consuming steps out of boxing your frame.”

The Hellwig Products Frame FX Kit covers a wide range of two-door A- and G-body automobiles. However, they are not compatible with convertible, wagon, or El Camino models.

If the Frame FX Kit seems like something your A- or G-body GM vehicle needs, kits from Hellwig Products can be found on their website at or one of their preferred dealers. As of this moment, the 11102 A-body kit is going for $472.69, and the 11100 Frame FX  Kit only costs $457.89. Meanwhile, the G-body boxing kit runs a cool $506.44, which is an outstanding value considering what all you get with this kit.

  • GM A-body 1964-1967: PN 11102
  • GM A-body 1968-1972: PN 11100
  • GM G-body 1978-1987: PN 11104

Article Sources

About the author

Micah Wright

Raised on LEGOs by grandfathers who insisted on fixing everything themselves, Micah has been a petrolhead in training since age four. His favorite past times include craft beer, strong cigars, fast cars, and culinary creativity in all of its forms.
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