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Our line of ’55-57 Chevy parts has been developed in our R&D shop over the last 22 years. We have built our own and customer’s cars, finding practical ways to improve the drivability of these classic favorites. We take the approach of improving the stock suspension with bolt on parts, replacing the front suspension with a more modern unit, or updating to a complete new chassis! All these concepts have their advantages, and disadvantages. The use of big block engines in particular makes a big difference. Additional front weight will not help handling, requiring better shocks and sway bar. Maintainence access is tight. Power steering swaps are very difficult, requiring special headers and still putting a lot of heat into a 605 steering box conversion. Power rack and pinion set ups that are properly positioned for good geometry will run into big block oil pan interference.

You will find that all of these difficulties are minimized by using either our frame stub or complete chassis. The front mounted rack really helps with exhaust header clearance, as well as maintenance access. Note that most crate engines, small or big block, come with oil pans that do not work well in these chassis. GM sells a pan made for a smaller rear sump, part #14091490 for early big blocks, #14091356 for early Gen V with split rear seal, and # 12495360 for late Gen V with full circle rear main seal. These big blocks tend to run hot in any older chassis, so if you have that problem, you’ll find that the addition of an engine oil cooler will drop the temperatures up to 30°.

The ’55-57 Chevy rack kit presented a special challenge. For the geometry to work correctly, with no bumpsteer, the rack’s inner pivot point needed to match those of the lower control arms. (note that this is not the case in every type suspension, but is based on the position of the outer tie rod ends on the spindle) There simply is not any OEM rack with that dimension. Others have made attempts to use Cavalier and Citation racks, but these end up with tie rod either too long or too short. The steering arcs therefore do not match the suspension arc, resulting in toe in change with suspension travel, called bumpsteer, causing erratic steering.

We were able to locate a rebuilder that could narrow the racks main shaft while apart for rebuilding, and thus create a rack whose inner pivot points are correct. Special forged steering arms are necessary to maintain good turning radius, since rack and pinions typically have less travel than relay rod steering. If you are using dropped spindles, they must be the type that has a bolt on steering arm. We sell those, using 10 5/8" ’80-81 Monte Carlo Metric brakes.

We will be pleased to send you an instruction sheet with clear photos for more detailed info. Our system is mounted with brackets which replace the lower control arm bushing rear washers, and only need two holes drilled in the rear lip of he crossmember for a stabilizing bracket. This puts the rack input shaft near the block with the exhaust away for better engine heat control. Block hugger headers will typically not work. Cast iron ram horn manifolds come straight down off the exhaust ports and fit well. Sanderson CC-90 header also works well, and they will sell you just the left side if you had already mounted blockhuggers. Small blocks fit well, big blocks will not. Please see our frame stubs or chassis for a good big block installation.

We carry another type dropped spindle that uses larger 12" rotors. It has the steering arm cast in place and so will not work with a rack kit. The brake parts are listed in the instructions and are easily obtained at any parts store for those who like to save money, or from us to save time and hassle. We also have a variety of brake kits for stock spindles. Many folks don’t realize that the common cast iron brake kits out there use a ’68-72 Chevelle/’68-74 Nova combination that moves the wheel out ¾" from stock. We sell that too as the most economical version, and also another that uses a different rotor mounted on an aluminum hub. The hub saves weight and keeps the track width stock for those who need the clearance for larger tires. If you want extra style, we can get Wilwood and Baer, front and rear, drilled, polished, etc.

Your new disc brakes will need a new dual master cylinder and booster to work correctly. The larger 9" unit will provide more boost, but won’t clear big block valve covers. A proportioning valve is not necessarily required, unless you are using the same size tires all around. Taller rear tires have more leverage resisting the rear brakes, and so have a built in proportioning effect. Cutting line pressure more may make the rear brakes ineffective. The master cylinder is set up for 4 wheels discs, and will need a 10 psi residual pressure valve added to the line if rear drum brakes are used.

The tubular control arms for the Tri-Five are a real nice way to improve the looks and handling. We supply the bushings and ball joint, and you install the cross shafts from your original arms. Be careful on the lowers as there is a most definite front and rear to them. I suspect that some of the lack of positive caster problems we hear about are caused by the lower shaft being reversed and moving the lower arm back too far. We provide a molded urethane spring seat for the lower end of the coil spring. This does a great job of reducing NVH (noise, vibration, harshness) and gives a more refined ride quality. They are also removable for conversion to coilovers or Airride. The upper arm has been lengthened 3/8" and the ball joint shifted back ¾" for more modern alignment specs consistent with radial tires and hot rods with a raked stance (reducing normal caster). We suggest 1/8" toe in, zero to ½° positive camber, and 3-4° positive caster with power steering, 2° positive with manual steering.

The arms are TIG welded in proven fixtures for accuracy, using 1" × .188 mandrel bent tubing. Premium ball joints and rubber bushings are supplied. We use rubber since urethane tends to ride very harsh, and most customers are unhappy with them. If you prefer urethane, we can leave the bushings out and allow a $40.00 credit.

Sway bars are highly recommended to improve handling. Since ’55-57 Chevy did not come with factory sway bars, there is no such thing as a factory mount. As all sway bars from different manufacturers come with different mountings, they will need to be added to our front tubular arms before any finish is added. These bars really help keep the body level for better handling and greater comfort.

Speaking very frankly, the major advantages of tubular control arms are a better cosmetic appearance, an optional narrower track width for tire clearance, and the use of better alignment to match modern speeds, radial tires, and power steering. Tubular arms are not appreciably lighter than stock stamped arms, although they do deform less under heavy cornering loads, which can lead to more predictable handling.

We have stayed with 1” x .188 wall DOM steel tubing, rather than the larger OD tubes seen in competitors control arms. The engineering fact is that a larger OD, but thinner wall tube is not any stronger. And the larger diameter makes some of the necessary clearances more difficult, requiring those larger tubes to be mashed flat to be welded to the bushing and ball joint bosses. We would rather use the size tubing that allows an undamaged tube to be welded to those critical areas.

We normally coat our control arms with a lacquer primer, which readily accepts acrylic enamel finish paint. The acrylic enamel is one of the more impact resistance type paints and will resist chipping quite well. And it can be sprayed in a color that complements the paint scheme of your entire project car. We do offer a powder coating option which is unique in that we offer a wide choice of colors. It is often difficult to truly match a powder coat color to normal paint, so we would suggest a coating color that is an accent color instead.

Sway bars are highly recommended to improve handling. Since ’55-57 Chevy did not come with factory sway bars, there is no such thing as a factory mount. As all sway bars from different manufacturers come with different mountings, they will need to be added to our front tubular arms before any finish is added. These bars really help keep the body level for better handling and greater comfort.

Upgraded shocks are probably the best kept secret in hot rodding. Changing from a standard parts store gas shock to a premium aftermarket unit is as much an improvement as going from bias ply to radial tires! A Saturday morning a couple hundred bucks will pay dividends you can’t imagine. The same shocks form the basis for the coilover conversions. Coilovers allow you to tune the ride height and spring rate easily for a no compromise combination. Take the ultimate step to a single or double adjustable shock and allow tuning the damping of your spring action for amazing handling without a harsh ride. They really come in handy too allowing you to have soft shocks for normal driving, and then tighten them up for harder driving or a big load in the trunk when traveling. Imagine changing the characteristics of your suspension at the turn of a button!

Please see page 6 for a thorough discussion of our frame subs. Specific to the ’55-57 Chevy, our frame stub is the way to go with a big block installation. If your frame is in good shape, or already built, the frame stub is a great way to get most of the benefit of an entire new frame with a fraction of the expense and effort.

We can also supply the front section of this chassis as a stub (less engine mounts) to be added to the remainder of your stock frame. This provides the benefits of the front suspension without transferring the body. If the rest of your frame is in good shape, and is built in a way that already suits you, this can be a good way to go. Please see our frame stub info on page 6.