I had the 3.5" RC on my 2009 Silverado. After the first 5,000 I had to replace the upper ball joints. It was the kit with their upper control arms and under warranty. After a couple calls they sent me ball joints and I just had to pay for the install. Another 5,000 miles and the lower ball joints went out, I didn't keep the truck much longer. Put a BDS on my K2 and it's a night and day difference. I strongly recommend getting a BDS kit.