I am not familar with the Commo setup but the Chevs don't have a eccentric , just a stud on the TB linkage .
Holley make a kit to adapt T700 TV cable to Holley 4bbl carbs; maybe that would work for you.
Part # 12-121
Holley 20-121 - Holley Transmission Kickdown Brackets - summitracing.com
Hume performance have them but they are not shown in their online site.
Hume Performance