The story was the 69 SC/Ramblers ONLY received these "convertible" sub rails, and for years I believed it too. Then I got in a 69 2 door post 6cyl car it had these rails. I got a 68 in it too had the rails. So I figured AMC did this to all American after the 67 343 V-8 issues they had with needing to strengthen the body. I have found however that 66 Americans and early 68 Javelins have a HD steel plate INSIDE the rocker. The thickness of this brace is equal to , or a little thinker then the combined thickness of the other three pieces used to make the rocker up. Why AMC remover these on latter cars, I do not know. Andre " A.J." Jacobs, web page http://southtexasamc.tripod.com (830)-980-3165 , akjamc@xxxxxxxx Owner & Proprietor, South Texas AMC Andre " A.J." Jacobs, web page http://southtexasamc.tripod.com (830)-980-3165 , akjamc@xxxxxxxx Owner & Proprietor, South Texas AMC