front end part help needed

Hi everybody, I'm knew here,and not real slick with a computer so forgive me my ignorance or slowness.
I have a 67 dart race car that I'm looking to change my idler arm on and was comparing my 67 arm to my neighbors 68 arm . they are similar and was wondering why I couldn't adapt the 68 arm to work in my car(much cheeper).
thanks for any and all help in advance.
jeff r