So I bought this 2015 Sierra and it needs ball joints replaced. Only problem is I can’t get a straight answer about If I need new upper control arms or stock ones put back in. It currently has Rough Country arms but when I asked RC they told me that they should not be installed. ALSO I’m not 100% sure in the size of the lift. RC says it’s a 5” but it doesn’t seem like it. Just looking for some input. Thanks