Before we get into showing you how we upgraded the suspension on our A-body, here's a little background into why we did it. We covered the build and installation of the 427-inch stroker small block into our '68 Valiant in the June 2011 issue. With the new 427 under the hood, the car was so fast that some upgrades to the chassis were necessary. It literally became a safety issue. Let's face it, running 150 mph in a '68 Valiant has a way of forcing you to focus your attention onto items such as the suspension, brakes and oiling system!

Weight Reduction
While these A-Body cars are a little lighter than either the B or E-Body cars, they are still heavy compared to some of the other cars that show up to race on open track days. The power of the 427 inch engine does help to equal things out a bit, but weight reduction has always been one of the cheapest ways to go faster. Not only will a lighter car accelerate faster, but it will corner harder and stop faster than a heavy car. Knowing this, we decided to take a serious look at each component on the car to see if there was any opportunity to shave a few pounds. Because these cars are naturally nose-heavy, we focused most of our weight reduction efforts at the front of the car. We were able to save big chunks of weight with the aluminum cylinder heads and the aluminum transmission case. We found smaller weight savings by switching to Schumacher motor mounts, cutting some bracing out of the hood, changing anti-sway bars, swapping headers, and installing new brakes.

The suspension under the Valiant is stock configuration, although very few original parts are still in place. The original K-frame and suspension was replaced years ago with parts from a '73 A-Body car. The later model anti-sway bar was an excellent design, but the factory bar is too soft for track use, so it was replaced with a 11⁄8-inch diameter bar. This larger bar worked fine but was very heavy, so we went looking for a replacement.

With a little bit of research we found out that Hellwig had a selection of lightweight Mopar anti-sway bars fabricated from high strength steel tubing. By increasing the outer diameter of the bar, a tubular anti-sway bar is both stiffer and lighter than a solid bar. Hellwig offers 1-1⁄4-inch bars as well as 1-1⁄8-inch tubular style anti-sway bars. We decided to go with the 1-1⁄8 version even though that meant that our front roll stiffness would decrease slightly. We felt that a slightly softer front bar would work fine once we had finished with our other weight reductions up front.

An adjustable rear anti-sway bar was also fitted to the car to provide additional rear roll stiffness. This particular rear bar was custom built to work with the low ride height, but vendors such as Firm Feel offer similar rear anti-sway bars. This bar was mounted on the frame in an effort to reduce un-sprung weight. The end link location on this bar is adjustable, which allows us to increase the rear roll stiffness for autocross events.