64-66 vs 67-69 barracuda front suspension

Yup, frame width (both rails and K frame) got wider in '67. For the amount of modifications you'd have to do, you may as well just build your own.
Skip the Control Freaks and get stuff that actually fits from @HemiDenny .
HDK 64-66 A Body K-Frame Package
And if you want struts
HDK 64-66 A Body Torsion Bar Eliminator