On 69-71 Sweptlines both arms are the same, and park to the right side. On 61-68 models the wipers park pointing toward the center so the right side arm is curved opposite to the left side arm.
Do yours still use a nut to hold the arm on or have they been changed to the slip-on style.
I have a few of the bolt on style Sweptline wiper arms. Email me at
ashleys4@bellsouth.net if you are still looking for some.