The pressure rises immediately with a nudge of the cable. The slack I mentioned is just to where there is not enough tension to make the pressure rise at idle. I have full tension at WOT and full release at closed throttle.
My TV cable is not connected to the carburator. It's connected to the original throttle bellcrank setup on the intake manifold, which has a linkage rod to the carburator, and a different lever ratio.
The distance from the bellcrank pivot and the TV cable is almost 2 inches in order to get full pull and full release. If it was any closer I would only get about 3/4 TV cable throw, and zero kickdown.
Is it not the point to have full pull and full release at the correct points of throttle open/shut, or am I missing something?