QA1 Coilovers

QA1 builds its coilover shocks around a small set of valving tiers rather than dozens of model names, so the series name on a box tells you how much tuning control you get.

DS - Single Adjustable

One knob with 18 clicks of travel moves compression and rebound damping together. QA1 positions DS shocks for street cars and drivers who make occasional track or drag strip passes and want to return to a street setting quickly.

DD - Double Adjustable

Two separate 18-click knobs let you set compression and rebound independently. A QA1 representative quoted by ChevyHardcore described independent compression and rebound control as most valuable "in higher levels of racing programs," which is why DD is the tier most road racers and drag racers who tune at multiple tracks step up to.

MOD series

MOD series coilover kits use a lightweight aluminum shock body (QA1's Aluma Matic) with billet hardware, and are offered with DS, DD, or ALN valving inside that same aluminum package. Every MOD series shock is dyno tested and serialized before it ships, and is revalveable and rebuildable by QA1 or an authorized service center.

ALN - Ride Sensitive, non-adjustable

ALN shocks have no external adjustment knob. The valving is fixed at the factory for a comfortable ride, which fits a daily-driven truck or cruiser more than a car that gets corner-weighted for the track.

Spring rate is chosen separately from valving. The C10 front conversion kit covered below, for example, pairs DD valving with 650 lb/in springs; QA1 also sells universal coilover shock-and-spring packages where you pick the spring rate to match your car's corner weight.

Trucks like the C10 left the factory on coil springs in front and leaf springs in back, so QA1 sells separate front and rear conversion kits rather than a single coilover kit for the whole truck.

The 52622-D650 is a front coilover conversion kit for a 1963-1972 Chevy C10, sold with double adjustable (DD) shocks and 650 lb/in springs, priced at $4,790.95 at the time of writing. It replaces the stock coil-spring front end with a coilover-and-crossmember system plus new control arms. See more C10 lowering options on our Chevy C10 classic trucks page.

For the rear, QA1's MOD series rear coilover conversion kit (DM501-1301) is built around a 3 in. or 3.25 in. diameter axle tube and is priced at $2,249.95 at the time of writing. It's sold with DS, DD, or ALN valving, so a truck-arm or 4-link rear end can run the same adjustability tier as the front.

QA1, Viking, and Aldan all build coilover systems and conversion kits aimed at American muscle cars and classic trucks rather than import tuner platforms, so they show up side by side on the same C10 and muscle car build threads. Bilstein is the better-known name for monotube shocks on later-model trucks and performance cars, which makes it a common cross-shop for owners deciding between a muscle-car specialist and a monotube OE-style shock.

Where QA1 tends to stand out is the valving ladder (DS, DD, MOD, ALN) sold across the same vehicle-specific kit, so an owner can order the identical C10 or muscle car conversion kit and only change the shock tier to match budget or how often the truck sees the track.

Ride height on a QA1 coilover is set by threading the lower spring perch up or down the shock body, the same way as on most other threaded-body coilovers; see our coilover adjustment guide for the general procedure and a coilover spanner wrench to turn the perch without marring it.

On a DS shock, the single knob's 18 clicks move compression and rebound together, so there's only one dial to turn. On a DD shock, the two knobs are independent, so compression and rebound damping should be adjusted and tested separately. For install labor, parts list, and typical shop time on a conversion kit like the C10 front system, see our coilover installation and cost guide.

QA1 shocks are revalveable and rebuildable by the factory or an authorized service center, and select shocks carry a lifetime warranty once registered at qa1.net/Warranty rather than being covered automatically out of the box.