The large drag link which came out on the '69s was part number 3953221, totally a '69 era part number, close in number to the 3953227 pitman arm which was also a '69 part. There would have been no need for GM to produce the large drag link I posted a picture of above for the Trans-Am guys in '68 if they had an off-the-shelf part ready to go that year. While some '68s may have the "221" drag link, I think they were probably retrofitted later in the car's life.
-Jon