Let's face it, unless you're building a gasser, any car looks cooler lowered. Back in the day when suspensions moved on from beam axles and buggy springs this was achieved by using lowering blocks, cutting or torching coil springs, removing leaves from springs or reversing the spring eyes. These days the aftermarket offers up any number of lowering kits for most popular vehicles, making the job easier and definitely safer if it eliminates torched coils!
One of the most prolific suppliers of parts to lower old Fords and Chevys is Jamco, which can supply dropped spindles, lowered leaf and coil springs, and lowering blocks. However, anything other than a mild lowering job will bring a car's chassis closer to the suspension components, especially at the rear, where contact between the chassis and the axle itself is commonplace-and not exactly desirable! The solution is to C-notch the frame, essentially raising the part of the chassis above the axle to retrieve full suspension travel with lowered suspension. Why's it called a C-notch? Simply because once completed the resulting arch over the axle looks like a sideways letter C.
Circle City Hot Rods recently lowered a customer's '49 Chevy using Jamco components at all four corners, retaining the stock torque tube rearend and straight-six running gear. With a C-notch as part of the job, we camped out in their workshop with our trusty Canon to show you how it was done.
Jamco supplied 3-inch lowered...
Jamco supplied 3-inch lowered leaf springs, which incorporate reversed eyes at the rear, as well as lowering blocks, new shackles, shocks, and longer U-bolts (though these U-bolts are incorrect, as the Chevy uses squared-off U-bolts owing to the unique pivoting mounting pad. Jamco corrected the mistake immediately). Using either the blocks or the new springs alone wouldn't require any chassis surgery, but the combination of the two meant the C-notch was needed.
To drop the front suspension,...
To drop the front suspension, dropped spindles, new steering arms, and coil springs were sourced from Jamco, along with new kingpins, thrust bearings, and bushes. There's not much point trying to reuse the old ones if everything else is being replaced. The dropped Chevy spindle (actually a raised upright!) effectively raises the kingpin boss, in turn lowering the car. We ran a pair of these on our Project '49 Chevy for years before installing a Mustang II-based IFS, and they worked just fine.
When tackling a job for the...
When tackling a job for the first time, it's always good to have reference literature. If you've never removed the kingpins from one of these Chevys before, you may be glad for the help!
Compare the old with the new...
Compare the old with the new and you can clearly see the difference in spindle height. The shorter coil springs will further lower the car once it's on the ground.
In these pictures the suspension...
In these pictures the suspension is not supported (there are jackstands under the chassis rails) so the lower arms are in the same position in both images.
Moving to the rear of the...
Moving to the rear of the car, the original U-bolts were removed and the axle supported so the springs could be swapped out. This picture clearly shows the pivoting mounting pad used on these Chevys, and that the locating dowel on the spring is not located under the axle. As has been discussed in our Wrenchin' column of late, this is why you can't drop a later axle straight onto the springs, as it'll sit too far forward in the wheel arch. With jackstands under the chassis and a floor jack under the axle, the rear shackles and then the springs were removed.
The difference between the...
The difference between the old and new springs is pretty obvious, and the Jamco item has a reversed eye for further lowering too.
The front of each new leaf...
The front of each new leaf spring was installed first, using the stock chassis bracket and new hardware. The rear of each spring went in next, using the new shackles. These hang from curved brackets riveted to the underside of the chassis, and the shackles actually hang "upside down" with the spring eye above the eye of the bracket once the car is on the ground. Here the weight of the axle is holding the spring down.
These Chevys don't use what...
These Chevys don't use what we'd consider a "normal" lower spring plate, through which the U-bolts would pass, but rather employ two brackets per side, one of which mounts the shocks. These were blasted, painted, and reused.
After making a couple of different...
After making a couple of different shaped cardboard templates, the final C-notch design was cut from 3/16-inch plate on the bandsaw, and a centerline marked on each one, corresponding with another line marked on the sides of the chassis 'rails above the axle.
If it wasn't clear in the...
If it wasn't clear in the last picture, this view should help. We're looking from inside the trunk, with a section of the floor and wheelhousing removed. You can see the centerline and just about make out its corresponding line on the top of the chassis. This is the centerline of the axle. Here Matt Proctor is measuring the outside width of the C-notch. It should be 3/8-inch wider (taking into account the two 3/16-inch plates) than the chassis rail width, but it never hurts to check. The sides of the 'rails may not be exactly vertical for instance.