Its always beneficial to replace something that is warn out. When these 67 throttle linkages are old and warn out they could jam up with the carburetor stuck wide open. I have rebuilt the bracket on the firewall with bronze bushings and fixed all the wallowed out holes in the linkage and then everything works fine.
If you want to go the cable route you need to get the cable and the cable mounting bracket on the intake manifold and the pedal for 68 and later.
its all just time and money