Fits Chevrolet Silverado / GMC Sierra 2wd 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 and 2007 Classic Body
QA1's Pro Coil systems provide both ride height and valving adjustment.
On-the-car adjustable valving makes it easy to dial in your desired level of comfort and performance.
Adjustable shocks have 18 clicks of compression and rebound adjustment.
Easy, bolt-in installation with stock control arms or QA1 tubular control arms.
100% dyno tested and serialized.
Made in the USA.
The general rule that you can abide by is the heavier the coil the heavier the motor. A V6 or Straight 6 motor will generally use the lighter spring rates. The middle of the road weight will be set for your small block or LS applications, and the heaviest coils will be reserved for the big block motors. Now these are not rules set in stone. If you have a small block and are looking for a little better ride quality you can opt for the lighter coils to achieve that. In the same sense if you are working with a straight line or DRAG racing application you may opt for the light coils as well to achieve the weight transfer you need to get that good launch. When you are looking at the spring rate on the rear it's pretty simple. If you are looking for a better ride quality go with the lighter coils and if your application is more performance driven select the stiffer spring rate for handling. Don't get too stressed on ensuring you get it right the first time. The coils are easily interchangeable and are not too expensive so if you decide the spring rate you have chosen isnt quite right give us a call and we can get you a different set. If you are unsure give us a call. We are happy to help.