Tripp Williams

I bought an 08 Sierra 4x4 that was obviously lifted. I had some suspension issues and went to get the truck aligned and ended up having to replace the ball joints. The issue that i'm noticing is that the upper control arm seems to be over extended and putting stress on the ball joints. It was recommended to buy lifted knuckles to compensate for this, but apparently you can't get lift knuckles for a 4wd. I can't seem to find any definitive information out there about the best way to go about correcting the issue, and I do not want to change out ball joints every 6 months. The truck is lifted somewhere around 4-6 inches with 35" tires. Any help on this subject would be greatly appreciated!