If that is the braided lokar cable you need to ditch that cable. they flex and streach under pressure.

Been there and done it. if you shorten the throw enough on th carbs to get wide open you have very stiff pedal.

On my new tunnel ram I did the linkage like most of the SS/AH cars. flip the front carb around, use a bellcrank and a stock cable. I get wide open on both carbs without having to mod the pedal, and its the easiest smoothest linkage i have ever had. I will never go back to the enderle stuff.