There should be adjustment at three different places on the kickdown linkage. The horizontal rod that your photo shows, also on the vertical rod between the two bellcranks, and then the short rod to the transmission lever. (I'm going by the '69 version, maybe '67 is different)
Have you used all the adjustment on all of these?
As for the throttle cable, there should be a clamp at the back of the intake manifold next to the bellcrank. The metal part of your throttle cable goes in that clamp, it is adjustable back and forth for proper length of the throttle cable. The excess just hangs along the firewall.