Keeping the suspension parts...
Keeping the suspension parts lubricated is also an important part of making sure they travel and operate correctly. This grease is being sprayed on the upper control arm bushings.
While there remains some debate as to how much good bolt-on traction bars do, the truth is that Chrysler factory engineers were experts at rear leaf design. The rear axle sat approximately 1/3 of the total distance from the front mount, which drastically limited axle wind-up; a pinion snubber that would cause the differential to brace down on the floor pan was the recommended course of action. Brand X machines with leaf springs normally had the rear centered on the leaf package, meaning that the front of the spring had much more wind-up room. The 426 Hemi and 440 cars benefited from a massive pack of five springs on each side, with an extra half-leaf added to the left and two extra half-leaves on the right (this was due to the direction of engine torque, and the reason why rear-mounted batteries should be on the right, or passenger, side of the car). Depending on your needs, there are a wide variety of spring packages available for A-, E-, and B-Body cars, and many people select the Super Stock springs that MP offers. Of course, full-out cars often go to a four-link/coil-over shock layout for increased adjustability.
One final possibility is using the newly-released mono-leaf style springs as covered in Mopar Muscle last month ("All for One and One for All," p. 71).
Which shock is stronger? Looking...
Which shock is stronger? Looking at the barrel size, the unit on the left is; using a larger piston inside the shock will lower temperatures and increase dampening ability. The engineers design the valving and oil flow orifices to the shock's designed purpose.
Since shocks are often the simplest things to change and come in many variations, we saved those for last. Coupled with all of the possibilities mentioned above, selecting the right shocks is critical to making it all work properly. Shocks serve two main purposes: They control and dampen spring and suspension movement, and, in that capacity, they allow that suspension to travel at a given rate of speed and distance. This is critical to keeping all four wheels on the ground, regardless of application.
Shocks "bounce" (referring to the up-and-down movement of the suspension), "jounce" (upward suspension travel that compresses the shock), and "rebound" (downward travel that extends that shock). If a shock is worn, that chuckhole you hit by accident might cause the suspension to bounce more than once, and the wheel affected can leave the surface of the road entirely-not a good situation when you are moving two tons of B-Body around!
While this is the primary role of any shock absorber, there are special kinds of shocks that control suspension movement differently. Hydraulic shocks, which are oil-filled, non-gas-charged varieties, were OEM in the musclecar era; today you select that type or gas-charged shocks, air-filled shocks, and "load levelers" (which are used in conjuction with a coil-over spring). Gas-charged versions are oil-filled, then filled with nitrogen and sealed; the pressurized nitrogen keeps the shock cooler and prevents aeration of the oil during shock movement, ensuring solid hydraulic flow. Any car will see an improvement in handling with the installation of gas shocks over standard hydraulics.
The trick at the track has always been a 90:10-ratio travel front shock, but these are not recommended for use on the street; they will not control the car in handling situations and could result in an accident. Dual-purpose cars can use a 70:30 ratio or even a 50:50 ratio (for mostly street-driven machines) with good results. Many companies now offer three-way adjustable front shocks that you can dial-in to the dampening, or travel, ratio you desire. To have your cake and eat it, too, there are now some 12-way adjustable shocks available. At $150 per side, they are pricy, but will let you have the best of both worlds. If you are changing from heavy stock wheels to narrow, lightweight front wheels and tires (also a no-no on the street) once you get to the track, you can always simply swap in a set of 90:10s while the car is jacked up.
Shock length is critical to...
Shock length is critical to making sure the suspension is working. To check it, unbolt the shock's lower eye, suspend the car by the frame so the rear is hanging by the springs, and extend the shock; if you cannot get it over the eyelet, you need longer shocks. If the shock bottoms out, it can unload the back tires and cause spinning. One economical fix, though not pretty, is using aftermarket shock extensions (shown) or junkyard shocks from a '70-'73 Imperial; many new replacement shocks will not extend as long as the old Imperial versions.
The pinion snubber looks a...
The pinion snubber looks a lot better than traction bars hanging under the car. It prevents axle wind-up, critical in violent high-horsepower cars that want to climb the ring gear and turn the springs upside-down on launch. For street cars, the snubber can be set up an inch off of the pan for better grab; on street/strip cars, 1/4-inch to 1/2-inch space is good. The idea is to control the suspension motion and get the pinion angles correct as the car reacts under acceleration.