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Classic Car Suspension Retrofits from the SEMA show

chevy squarebody truck with ridetech suspension

For decades now people have been retrofitting classic cars with more powerful motors, disc brakes, and the latest multi-speed transmissions, with little done to the chassis itself. Sure, most hot rods and customs were lowered, on stiffer springs (or airbags) and better shocks, but they still plowed like a tractor, despite being upgraded to modern radial tires.

A funny thing happened in the 21st century though; modern cars got too good. Everyday front-wheel drive family sedans are accelerating better than many formerly “fast” cars from back in the day. Somehow, they also ride like luxury cars and handle better than old sports cars. Even minivans and SUVs are handling, riding, and stopping better than old cars, while being just as fast in many cases.

In order to be more than just a nostalgia trip, modern suspension engineering and design would have to be fitted to the old cars we all loved. Luckily CAD/CAM technology and CNC machining and welding have made it affordable to design and produce these parts in very small batches. The technology also allows on-demand manufacturing and shipping in many cases, something unheard of back when every part was custom and handmade.

Now that old cars can turn and stop, many of them are being taken to tracks other than the drag strip. The Optima Battery Ultimate Street Car Series hosts track days around the country specifically for these new age muscle cars. More and more often car shows are also including coned off, parking lot autocross courses open to anyone with a couple of buck entry fee. And of course, the changes make these cars much more enjoyable on a weekend drive along your favorite mountain road as well.

1960s-1980s Chevy/GMC Trucks

When the price of the classic muscle cars skyrocketed a decade ago, the hobby started to embrace trucks a bit more. Some of the most popular trucks being built these days are the “square body” Chevy and GMC made from 1973-1987, and the two previous generations going back to nearly 1960.

QA1 1963-72 Chevy/GMC Truck Suspsension

The earlier trucks used a unique twin trailing arm design, with coil springs out back, that somehow became the basis of NASCAR stock car design. Now, QA1 has re-engineered that basic system to work better, with more adjustability, and better handling. The heart of the system is their multi-adjustable coilover shocks, but they also made all new brackets and control arms. The new kit more positively locates the rear so you can corner harder, and put down more power.

Part of the draw of the square body trucks is that they came from the factory fairly well set up, with power disc brakes in all of them, power steering in many of them, and even electronic fuel injection in the final year. But under the skin they are still crude trucks, with leaf springs in the back and front suspension designed to be strong, not to corner well. Now you can get bolt in rear 4-link kits from Ridetech or Heidts that make it much easier to lower the truck and improve the handling. Out front, you can either bolt in a whole new subframe (Heidts) or just install re-engineered A-arms (Ridetech) for modern car handling.

Chevy Camaro and Pontiac Firebird (GM F-Body)

Still just as popular as ever, the Chevy Camaro and Pontiac Firebird continue to get the pick of upgrade parts first. The third generation cars that debuted in 1982 were a revelation in their handling, for the time, but times have changed. The second generation car, which is admittedly cooler looking, suffered with a chassis barely upgraded from the 1967 version, which was largely based on the Chevy II from even earlier.

GM F-body bolt in 4-link
GM F-body bolt in 4-link - interior

Those early 1970-81 GM pony cars were fairly crude, mostly having light weight and an aerodynamic shape going for them. Out back was still just leaf springs and a solid axle, just like a pickup truck. Now Ridetech has a bolt in triangulated 4-link system, that converts it to coilovers and control arms. The forward mounting for the upper arms bolts to the floor inside the car, under the rear seat. The whole thing is better engineered than the Mustang system that Ford introduced in their car in 1979, and sold until 2003.

GM F-body independent rear suspension

The all-new for 1982 F-body used a much improved rear suspension with 3-links and a Panhard bar, but for even better handling Heidts now has a fully independent rear design. Heidts’ system bolts into the third and fourth generation cars, and can be used to get handling on par with a Corvette or the latest 21st century Camaro. They also offer full IRS kits to fit the early cars as well, so you can make your 1970 1/2 Camaro Z28 handling match the looks it had from day one.