Chris Alston's Chassisworks
G-Bar Canted 4-Bar Rear Suspension
Chassisworks g-Bar canted four-bar rear suspensions are a unique and effective approach to rear axle location. The lower links connect at the leaf-spring pockets, and when combined with the canted upper links, securely control the rear axle to create a precise suspension-travel path, eliminating the need for a Panhard bar. The upper and lower mounting brackets also have multiple positions to adjust chassis anti-squat and handling, and both upper and lower links are length adjustable to set pinion angle and suspension preload. Double shear lower shock mounts and three-position upper shocks provide over 4 1/2 inches of ride height adjustment.
gStreet Coilover Conversion
For those wanting to keep their stock subframe, the gStreet coilover conversion uses the factory mounts, and bolts directly to stock or aftermarket dropped spindles. Single- or double-adjustable billet VariShock coilovers or ShockWave air suspension is optional, but each style features a pivot-ball lower mount with ball-stud upper mount that bolts directly to the factory mounting location. Drag racers may want to substitute a specially valved VariShock with low-friction COM-8 spherical-bearing lower shock eyes, which enables finer control of front shock extension, and vehicle weight transfer.
G-Machine Subframe Package
The g-Machine subframe is designed to dramatically improve handling, braking, and steering with Alston's own double-adjustable, billet-aluminum VariShocks, extra-large antiroll bars, double-adjustable upper A-arms, reinforced lower arms, 13- or 14-inch brakes, and power rack-and-pinion steering. Thanks to careful engineering, tires up to 10 inches wide will fit inside '67-69 Camaro/Firebird and '68-72 Nova fenders. Clearance for headers and oil pans is also greatly increased.
g-Machine subframes are direct bolt-ins, as are gStreet coilover conversions. g-Bars are typically bolt-in, but some applications may require minor modifications for fitment.
g-Machine subframe starts at $4,478, gStreet conversion start at $1,698, g-Bar systems start at $1,839.
Detroit Speed & Engineering
Hydroformed Subframe Suspension Package
In a marriage of OEM technology and hot rodding, DSE's exclusive hydroformed framerails offer uniform strength and rigidity and precise repeatability, thanks to the low-temp forming process. The unique suspension geometry built into the tubular control arms, C6 steering knuckles and bearing packs, power rack-and-pinion steering, and splined sway bar not only work to improve handling, but also ride quality. Plus, up to a 10-inch-wide wheel can be packaged without modification to the inner wheelwells.
For dramatic upgrades to the stock subframe, the Speed Kit 1 offers bolt-on tubular control arms, Koni Classic shocks, 2-inch drop front springs, and a tuned front sway bar. The Speed Kit 2 steps up to a Koni aluminum body coilover conversion, while the Speed Kit 3 adds a DSE 600 steering gear with rag joint and pitman arm, DSE tie-rod adjusters, and inner and outer tie-rod ends with idler arms.
For an easy rear upgrade, DSE's leaf-spring Speed Kits provide a noticeable increase in handling, thanks to several revised spring rates and a choice of either a 2- or 3-inch drop. With heavy-duty shackles and Koni Classic shocks, it's a basic package that works.
QuadraLink Rear Suspension
Swivel-Link technology allows the QuadraLink to fully articulate with smooth motion and zero bind. Rather than Heim joints, tuned high-durometer rubber bushings are used at all attachment points to isolate road harshness. The long upper links provide great pinion and U-joint angle control, and the Panhard rod is adjustable as ride height changes for roll center control. The rear upper shock crossmember also serves as a brace to strengthen the rear body and frame section.
While the front subframe, Speed Kits, and leaf-spring packages are bolt-in, the QuadraLink requires some significant cutting of the floorpan and framerails.
$6,700 for the unassembled bare steel subframe kit, the front Speed Kits start at $1,823, rear Speed Kits are $683, and $2,195 for the QuadraLink (with coilovers included)
Fat Man Subframe Package
Fat Man's subframe features revised suspension geometry with a 2-inch narrower track width for wide tire clearance, and despite a low-slung stance, gains roughly 2 inches of ground clearance at the front crossmember. Front-mount-style rack-and-pinion eliminates header-to-steering box interference while still bolting to the original column. Polished stainless steel control arms, G-Tech spindles with 11-inch disc brakes, billet QA1 coilovers, and a sway bar are standard. Ridetech air springs and Wilwood brakes are optional.
G-Tech Spindles and Tubular Control Arms
G-Tech spindles not only have 2 inches of drop for a lower center of gravity, the upper ball joint has also been raised 2 inches to improve the camber curve, and the steering arm position has been optimized to eliminate bumpsteer. Fat Man has seen as much as a 20 percent improvement in skidpad numbers with just the spindle upgrade. G-Tech tubular control arms are built from TIG-welded DOM SAE .188-wall tube steel and CNC-machined billet steel offset upper control arm shafts. A relocated upper ball joint position allows performance alignment specs without massive shims stacks, and proprietary urethane bushings provide control without harshness. Plus, stock or narrowed length is available for extra tire clearance.
G-Tech Spindles and control arms are bolt-ons for stock and some aftermarket subframes. The subframe bolts to the unibody using original mounts, and according to Fat Man, the swap can usually be performed without removing the engine.
$299 for the spindles, $899 for the control arms, and $4,295 for the complete front subframe package