There are three different front suspension options on the 2014 to 2018 Silverado and Sierra 1500 series four wheel drive trucks. You can tell the difference by looking at the lower control arms. We have a chart listed here to help you find the style that your truck has. The reason that you can’t mix and match between the suspensions is due to different ball joint sizes.
There is also the Magnetic Ride Control option (MagnaRide) On those trucks you can’t change the front struts but can still use a spindle.
There are also two different rear suspension options, with magnetic ride control (MagnaRide) or without MagnaRide. If your truck has MagnaRide you can not replace the rear shocks. For those trucks you can only use a shackle along with a set of shock relocators.
If your 2014 to 2018 Silverado or Sierra 1500 four wheel drive has the cast steel lower control arms then you can’t use the Belltech lowering spindles because they will not fit. The best way to lower these trucks is with a set of adjustable struts. The struts are adjustable from 2 inches of lowering all the way up to two inches of lift. Keep in mind that no matter where you set them you should get a wheel alignment once you are satisfied with the ride height.
But with only 2 inches of maximum front lowering available it limits your rear lowering amount. The easy way to do it is with a Belltech 6401 shackle and removing the factory blocks for 3 inches of rear drop. If you do want to go with the four inch rear drop then you’ll be installing a flip kit and lowering the back of this truck more that 3” will require you to replace the rear shocks with a shorter set.
If you decide to lower the rear more that 4 inches then keep in mind that your truck will be lower in the back than in the front and in the world that I live that is not a currently acceptable style on a lowered truck.