You don’t need the Chrysler throttle cable holder or the Edelbrock throttle adapter if you use all of the Lokar cable system parts. This also applies to the transmission kick down set up.
Both are easy to use. BTDT several times.
In the picture above (Post #3) the throttle lever should be on the rear carb for a progressive linkage set up as pictured. But make sure that both carbs fully open when the pedal is on the floor for wide open throttle.
The linkage attachment point on the front carb should not be at the same point but higher up. Look below at my (very old) video of my dual quad set up near the end where I have my friend move the throttle a few times. You can probably see the attachment points are different. The video is a little grainy.