The GM engineer who designed the original A-body suspension system back when John F. Kennedy was president would probably be shocked at how far his suspension has evolved in the last 50 years. The earliest Chevelles, Tempests, F-85s, and Buick Specials were simple, midsize machines that now are among the most popular Pro Touring platforms on the planet. Global West started building parts for Chevelles as far back as 1980 and recently has come up with a really slick bolt-in rear coilover shock conversion that requires no fabrication skills other than drilling a couple of holes.
Coilover shocks may at first seem a bit overkill for a simple street Chevelle. But not only does it offer the advantages of a much wider selection of rear spring rates but coilovers also offer easy ride height adjustments just by spinning the adjusters on the shocks. Finally, depending upon the style of coilover shocks you choose, you also have the ability to adjust the shock compression/rebound and set the chassis up for either handling or ride quality.
Earlier coilover conversions involved welding, but the Global West kit is designed as a simple bolt-in with no metal fusion required. The most we had to do was fabricate a couple of simple spacers and drill eight holes. The spacers were used only because our frame was a little bit different. Global offers five separate parts numbers split up between the early 1964-’66 cars and their 1967-’72 cousins. Because 10- and 12-bolts are interchangeable, these kits will work with either rearend assembly. Because the lower shock mounts are similar, this Global kit should also work with only minor changes for either a 9-inch or Strange’s Dana 60 dubbed the S-60.
We chose to install the Global system using double-adjustable Viking shocks on a 1966 Chevelle frame that had just returned from the powdercoater. We also decided that it was bad form to invest in a set of coilover shocks and yet still run those spindly stock upper and lower control arms, so we also invested in a set of Global West tubular lower and adjustable upper arms. The adjustable uppers now allow us to set the pinion angle exactly where we want it. This is really nice for setting the proper driveshaft angles (“Get Your Angle On,” Feb. ’15). With the body removed, we chose to install the kit with the frame on the shop floor upside down to make it easier to install. Because of this, the photos may take a moment to get used to the different orientation. But no worries—the entire install only required a few hours over a Saturday afternoon but photos tell a much better story than mere words, so let’s get to it!
01. We thought we’d show you how good this conversion looks totally installed right from the start.
02. You can purchase the entire kit either with or without shocks. The best part of this kit is that you can leave the MIG welder covered up in the corner of the shop—you won’t need it.
03. The first step is to remove the original rear shocks and bolt the drill guide in place in the two original 5/16-inch upper shock mounting holes and drill the remaining hole to mount the upper shock mount. Remember, we’re looking at this with the frame turned upside down. Just imagine you’re in Australia.
04. Next, loosely install the left and right L-shaped upper shock brackets into the frame with the supplied 5/16-inch bolts and nuts. There’s a backing plate that sits on top of the frame that the bolts fit through to create a flat area for the nuts to tighten against. Do not tighten any of the fasteners just yet.
05. Now install the crossmember in between the shock mounts. It can only bolt on one way. The crossmember creates a double-shear upper mount for the shock, which is critical because now it will be supporting the car’s entire rear load. Install the 3 1/2-inch long, 1/2-inch diameter bolt through the upper shock mount to the crossmember to line up all the fasteners and bolt it into the frame on both sides.
06. With the large shock bolt through the crossmember on both sides, this will align the crossmember with the frame so the six 3/8-inch boltholes can be drilled. Drill one hole, place a bolt in the hole, and then alternate sides until all six holes are drilled and the bolts are in place.
07. Sometimes the coilover crossmember may not exactly lay flush with the frame brace. If that’s the case, a small shim or washer can be placed in between the coilover crossmember and the frame brace.
08. Here is the coilover crossmember installed in the frame while it is still upside down.
09. Next, remove the lower control arm at the rearend housing. We had already stripped the frame and are going to use new Global West tubular lower control arms. Install the 1/2-inch lower control arm bolt through the lower shock mount and control arm and then place the mounting bolt from the new mount through the old shock mount bolthole. Perform this for both sides.
10. Using a 1/2-inch drill bit, drill the third mounting bolthole for the mount on both sides and install and torque all the bolts to locate the lower mount.
11. Now install the shock into the upper mount—this photo looks odd because the frame is still upside down. With the shock hanging from the upper mount, bolt it to the lower mount and torque the upper and lower bolts to 70 ft-lb.
12. To initially install the Global adjustable upper control arms, we set them to the length of the stock arms. Later, with the car at its ultimate ride height, we can set the best pinion angle for the driveline.
13. Here is the entire system installed on the frame along with Global West’s tubular lower and upper control arms. We also installed a pair of Global frame stiffeners. These ensure the factory upper crossmember does not crack where it is welded to the frame. Originally, only big-block cars came with factory stiffeners.
|1967-’72 A-Body Rear Coilover kit, Viking shocks||COR-672V||Global West||$1,045.00|
|1964-’67 A-Body Rear Frame Supports||TS-47||Global West||$129.39|
|Rear Lower Tubular Control Arms, Del-A-Lum, Spherical Bearings||TBC-4||Global West||$379.60|
|Rear Upper Adjustable Control Arms||TBC-47||Global West||$299.00|
Interested in more suspension tech?
How to Upgrade Suspension on a 1967 Chevrolet Chevelle
Here’s One Way to Improve the Handling of Your 1966 Chevrolet Chevelle