68 dart sway bars?
Yeh. They did. If you try and adapt a used one you must be careful. AT the change in K members, 73/ later the bar was bent different and went inside the hollow K
72/ earlier went under the K
The tabs on the lower arms are different 72 earlier, and 73/ later
Hotchkiss and PST both offer aftermarket kits, I don't know who else
Anti-sway bar is a VERY desirable feature.