HELP with Control arm shafts
 

I have been told that the control arm shafts have an indentation on them where the u-bolt is suppost to ride. Is this true or is that indentation just a factor of the u-bolt riding on there for 44 years? If this is true how are you suppost to know which shaft goes to which arm and which way they go? Please help I want to put my lowering springs in this weekend and have no clue here.