Can I buy a 3 inch lift for my pickup without buying the steering arm i think called idler arm correct me if i'm wrong.

 

Its called a drag link and no you dont have to have one but its recommended. I just installed a 3 inch lift and i lost some of my turning radius. You will need to do somthing with your torque bar(bar that mounts from the axle to the frame) either buy an adjustable one from rancho or custom make somthing.