1964 -1972 GM A Bodies: Revisiting History with Modern Suspension

We recently visited 1964 -1972 GM A Bodies here on The Engine Block, fan-boying over their legendary status as performance juggernauts. We also spent a little time exploring the room for improvement left by those factory suspensions. As promised, we’re back to tackle some of the best aftermarket products and suppliers to consider when beefing up that muscle car—as well as some tips and tricks on how to get that upgraded suspension dialed in.

Geometric Parts

As we pointed out last time, there are some serious weak points in the front end of many GM A Bodies. One major issue lies in the control arm placement, dictated by a short spindle height. These vehicles were designed to allow for more understeer, as oversteer was an inherent problem.

In addition to the placement of the factory control arms, their construction leaves something to be desired as well. Like a lot of stamped-steel equipment, these stock pieces were quite weak and tended to crack. While breaking away from 60s glory hurts the heart, upgrading to aftermarket control arms can easily correct this problem, increasing rigidity and correcting geometry. Quality bolt-in units can be purchased from reputable brands like QA1 and Hotchkis.

Side note: You may notice that I name drop these brands whenever I get the chance. For the record, I don’t have any professional affiliation with these names, but I’ve worked with both and even used QA1’s suspension components on my personal ride. In my opinion, both brands offer tight, bolt-in product that works very well. No issues with fit and finish, and the performance is awesome. (It also helps that they have extremely reasonable pricing for what you’re getting.)

Control arms are but one issue, though. We still want to look at sway bars, shocks and springs, the chassis and even that rear end.

Sway With Me

For many, the big thing with GM A Platform rides is getting body roll under control. The weak structure and placement of the control arms contribute to the body roll of these vehicles, but the real culprit is the weak sway bars. So, adding these parts to the list is essential to handling performance.

Now, some owners will work around the front end, as this is where most of the contributing factors of body roll are present. This means, adding a stiff bar to the front alone is going to work right into your budget. However, if you’re hellbent on getting the car to handle as best as possible, you need to tie up the ass-end as well. (Aftermarket shocks and coils will help with this too—something we’ll come back to in a bit.)

Sway bar installation may seem a little intimidating if you’ve never done it before. But if you can put control arms on your car—a sway bar will be no match for your hands. With that in mind, on a vehicle like the Chevelle, where sway bars are already present on the front end, it’s as simple as unbolting the old unit, replacing the mounts, and bolting the new unit into place. Of course, Hotchkis and QA1 will have what you need to get this done.

Reinforce the Rear

Now, let’s talk about the tail end. One of the things that really gets me all rosy in the cheeks and weak at the knees with these cars is the use of a factory 4-link. I mean, hubba hubba. But while it’s got advantages in terms of launching, it’s not perfect.

The first step any self-respecting Chevelle owner with even mild small-block power should do is install a pair of rear crossmember braces. Edelbrock, Hotchkis, Year One, OPG, and others sell different versions of this factory piece that connects the front upper and lower control-arm mounting points. This triangulates the rear crossmember and prevents the crossmember from cracking with the torque of violent starting-line launches. It’s also a good idea to carefully inspect the rear crossmember for cracks, especially around where the crossmember attaches to the frame. -Super Chevy

Super Chevy also recommends adjusting the pinion angle to point 2-3 degrees down. This is done with adjustable upper control arms (which you can also source from the above suppliers) and helps keep the pinion at a neutral angle while launching.

Don’t Deflect

Another issue with GM A Bodies’ rear suspensions—in this case, the Chevelle—is that the rear lower control arms were designed to deflect in an effort to prevent binding. This is a big problem for owners looking to put big beefy tires on the rear of their rides.

Again, Super Chevy: “The solution is a lower control arm that does not deflect. Some factory lower arms came boxed to accommodate mounts for a rear sway bar. The next step was tubular lower control arms much like those from Global West, Hotchkis, Art Morrison, and others. The most interesting one is the Global West tubular arm equipped with a spherical bearing in the front pivot point.”

“This allows a certain amount of movement without binding. For straight-line applications, polyurethane bushings do a good job, but add body roll into the equation and it’s possible to create bind in the rear suspension. The beauty of the tubular lower control arms is that you can now run a much larger rear tire with less clearance to the body without worry of a tire rubbing, because the rear-axle deflection is significantly reduced,” finishes Super Chevy.

Shock It to Me

With the right moving parts, you’ll see a big benefit in performance, but the factory spindle height is still going to create some issues with understeer. How can you correct this? Stiffer springs in the front end.

Investing in coil springs that stand up to the task isn’t something that will kill the budget. In fact, on a classic platform like this, it’s something that’s probably already needed. Stiff springs all around the car will help with body roll. But to really get the most out of them, you should consider setting yourself up with a good set of shock absorbers in all four corners. These upgrades alone should help a great deal with the poor riding characteristics—even to the point where many drivers will be happy enough to stop here.

For shock and coil spring selection you do have a range of options to work with. Ridetech, Hotchkis, and QA1 are all great performance brands to lean on when it comes to coil overs. For shocks, you can still lean on these names, but Monroe, Bilstein, KYB, and plenty of other brands join in the fight to give you a variety of street and competition level shocks which will really help you dial in the comfort and performance of the vehicle.

Fix the Flex

The chassis of GM A Bodies are fairly rigid, as they utilize a full frame. But this does not come without its own issues. Frames can still flex. And, actually, an issue many complain about is sagging in the frame. Let’s also not forget the instance where you are running a convertible car, where flex becomes more of a noticeable issue on account of there being no roof to help tie things together.

Now, frame sag does happen—but it’s not like the car will just fold in half. So, for you run-of-the-mill Chevelle and GSX guys pushing the limits, the frame is good. But for peace of mind, reinforcing the frame is far from uncommon. Speedtech and Hellwig Frame FX make weld-in reinforcement kits that solve these issues and keep that chassis super stiff.

Now a stiff frame is a cherry on top. Not every owner is going to sign up for it and many can live without. Though, a stiffer and geometrically-correct chassis is going to help plant power on the ground and keep it there. Though, unless you are running a convertible or are in serious competition, this upgrade is likely one you can live without.