cbodybob and i just talked this through . 65 c body 2-4 dr h/t & conv use nags #w657 , 4 dr 4 dr s/w use nags # w658 . 66 c body 2-4 dr ht use nags # w657 , 4 dr 4 dr sw use nags w658 . 67 c body 4 dr ht and conv use w657 , 4 dr 4 dr ws use w658 , 2 dr ht uses nags # w692 . this is new for 67 . 68 c body 2 dr ht uses nags # w692 , 4 dr ht & conv use nags #w657 , 4 dr 4 dr sw use nags # w658 . sorry if there was any confusion . this is straight out of my body shop glenn michell manual for collision estimatior guide . i hope this helps .