Chevrolet Suspension Upgrade - Stand And Deliver, Part II

While we’ve still got the plasma out, we might as well cut the C-notches out and get those installed. If you don’t have a plasma cutter, a cut-off wheel on a die grinder works too, just be mindful of those brake and fuel lines again! There is a plate attached to the bottom of the framerail that supported the top of the coil spring that needs to be trimmed flush with the edge of the frame before we can move forward.

Next, using the C-notch kit as a template, the area to be trimmed can be marked on the framerail. There is a factory hole on the framerail that is used for reference to line up the C-notch.

Here you can see the area that will be trimmed away. The elongated hole on the left is the one used for alignment purposes.

We cut the offending section out again using the trusty Lincoln Tomahawk 375 plasma cutter. Shown is the driver’s side (we did that one second and it turned out much nicer!).

With the section cut away, it is necessary to remove a few rivets on the bottom of the framerail as these will be used as attachment points. With the C-notch kit in place, the remaining holes are drilled to accept the provided 7⁄16-inch hardware.

Once all the mounting holes were drilled, we hit the framerails and C-notch kits with Summit Engine GM Black spray paint. This stuff goes on great and leaves an even, satin finish.

Here’s the driver’s side C-notch bolted up and ready to rock. Note the 3 inches gained over the bottom of the stock framerail. Beefy is an understated description for these heavy duty C-notches!

This is the elongated hole that we referred to earlier. Note the relation between it and the front edge of the C-notch.

Next up is to install the 5-inch-dropped coil springs. The number on the side of the spring, 603-5, denotes the application followed by the amount of drop. Note the low-profile bump stops on the axle kick up and the use of the upper coil spring retainer under the fastener on the spring.

Before the trailing arms can be mated to the coil springs, another set of retainers need to be installed and properly clocked in the spring. The retainers feature welded nuts like the factory to ease installation.

Now it’s time to loosely attach the front of each trailing arm to the crossmember, followed by each spring retaining fastener.

An ant’s eye view shows the trailing arms, drop center crossmember, C-notch kit, and dropped springs ready to accept the newly rebuilt Currie-prepped 12-bolt rearend.

Before the rearend is installed however, we need to address the stock shock mounts, necessitated by the lowered nature of the rearend. Here, you can see the two holes where the stock mounts were originally riveted in place.

Once the stock mounts are removed, the new relocation mounts bolt in their place.

You can see the difference in the upper shock location here. The new mounts correct the shock angle on lowered trucks and allow for proper shock travel and geometry.