rear suspension binding
 

Im working on a new project of mine. A 79, and ive been looking into suspension and options and im trying to get a grasp on a lot of information ive been seeing. One thing I read about is binding, binding when the car gets lowered.

2 questions,

what parts exactly bind? and what's the reason?

do they really bind when just lowering a little? like 1" -1.5"? or is the case when "slamming"?

thanks