The problem w/ your throttle linkage is the leverage ratio you have it set at. I would move the linkage end higher up the carb lever to the large hole. This will require a bushing. Then of course check for WOT function but your linkage end is just too close to the shaft.
https://www.summitracing.com/parts/h...yABEgLppfD_BwE
But even better would be to fab a cable throttle like Shaky did & do away w/ the bellcrank system altogether.