Gentlemen, I have owned 3 chevelles, and it is my pleasure to still have 2. I am often asked if my car came with boxed lower control arms, limited slip differential and rear anti-sway bar, and I have answered that these were available on Chevelle SS 396, but were extra cost add ons. Once or twice I have suggested that some of the cars with slightly higher price tags such as the Judge or some Ram Air GTO's or possibly 400 or 455 cid Cutlass 442's had it standard. Then, I got to thinking "Did I really know what the heck I was talking about?" Did these cousin cars and the Buick GSX come with some of the premium packages standard, or were they extra cost items? R.B.