GM A Platform: Even Champions Have Their Faults

The Buick Skylark, Pontiac Tempest, Oldsmobile Cutlass, and Chevrolet Chevelle. If these names don’t get the hair on your arms standing up—well, you’re dead inside. I don’t care if you’re a Ford guy, a Mopar guy, a truck guy, or even an import guy—we’ve all had daydreams of tearing up the road with a GM A platform vehicle of some sort.

The GM A body likely plays host to some of your favorite muscle cars. The rides sitting on this platform have been some of the most aggressive in both appearance and power. Need proof? Well, the models I mentioned above are no minor threat on the streets and no strain on the eyes. But while the GM A platform boasts a legacy that supports keeping them in stock condition, the best builds will take the time to reinforce the inherent weak points in these vehicles—making them the best they can be.

Putting the “Muscle” in Muscle Car

Pinpointing the weaknesses in vehicles like the Chevelle, Cutlass, and Skylark feels like blasphemy, I know. These rides are renowned as absolute juggernauts and, for most of us, need zero introduction. While base models can steal the show, the badges SS, 442, and GSX will drop jaws and send potential foes running.

Why? Because they were power mongers! In their prime, these vehicles hauled from 0-60 somewhere around 5 seconds flat. In factory form, they could cut down the quarter mile in the mid-13s—and that was on skinny, inadequate stock tires. Let’s also not forget that the GM A platform was host to what was considered to be the most powerful muscle car from the era: the 1970 LS6 Chevelle SS.

Power wasn’t something that was just reserved for under the hood. Look at these things! The designers were able to directly reflect the brutal personality in the appearance. They’re square, they’re angry, and above all—they’re beautiful. On the silver screen, these cars may not have been put on the same platform as other Hollywood favorites but, rest assured, that if one rolls up on you, you will feel star struck.

Pick Your GM A Platform

In order to get a true historic overview of the GM A body, we need to talk about when these cars were produced and what our particular focus is today.

To start, the GM A platform kicked off in the late 1930s, running up into the late ‘50s. It was reintroduced in 1964 and, from there, became host to the vehicles I’ve been since gushing over. This phase continued until 1981, at which point the A platform was transformed and designated as a front wheel drive platform. Total buzzkill, right?

Well, not to worry, because the existing rear wheel drive vehicles on the A platform were then titled as G-bodies. And we find a few gems on this platform as well, as the ‘80s gave us the Monte Carlo, Cutlass, and Buick Grand National.

As I said above, these vehicles were absolute beasts in stock form—but they still have their limitations. In our quest to find their weak points, we’re going to limit our discussion to GM A platform vehicles from 1964-1972. (And, believe me, even that is painting with a broad stroke.) However, later models on this platform and even G-body owners will be able to squeeze some juice from this discussion as well.

Correcting Things, the Wrong Way

So, out of the gate, the drivetrain was as solid as could be in GM A bodies. Even with smaller displacement V8s, you were still getting your hands on the legendary GM engines and transmissions. While these were limited by industry standards of the day, they really need very little help in order to shine.

To find the real limitations of these cars, we should direct our attention to the suspension. Looking at ‘64-’72 Chevelles, Hot Rod Magazine points out, “In no particular order, these [weak points] include stupid-soft front coil springs, piano wire that doubles as a front sway bar, and an aggressively poor camber curve. This terrible camber exercise is dictated by a short spindle height that creates an increase in positive camber anytime the front springs are compressed with body roll.”

Now, one thing that can be very frustrating for owners of A-platform cars is that GM intentionally built the suspension with weaknesses. This was to correct issues of the rear 4-link binding up, as well as the inherent oversteer issues of the era. Does this mean these cars are undrivable? No, absolutely not. It just means there is room for improvement.

Other major issues on the roster are the weak-stamped steel control arms in the front of the car and the soft shock absorbers from the factory. Though, these don’t exactly come as a surprise, as during this time just about all of Detroit’s muscle suffered from the same issues.

Why Bother?

I get it. I’m giving you some conflicting information here. On the one hand, I recommend ditching most of the factory components and replacing them with aftermarket parts. And in the same breath, I’m telling you these cars aren’t that bad. Well, they are and they aren’t. Sure, you can drive stock vintage muscle with impressive results, but doing the right work is going to make a big difference.

Correcting geometry, replacing factory parts with beefier units, and swapping springs and shocks will result in a reduction of slop, body roll, and lack of traction. This will help you put every ounce of that GM power on the ground and keep the car driving wherever you point the steering wheel.

So, what’s entailed in a GM A platform suspension overhaul? Stay tuned, as we’re going to tackle just that in our next post. From choosing the right parts and suppliers, to getting those components installed, we’ll have you flexing more muscle from your muscle car in no time.