I have been struggling yesterday afternoon and all day today with the stock linkage throttle linkage on the 57 Bird Fordomatic and progressive linkage for the 3x2 carbs. The combined spring resistance of the 3 accel pumps in the carbs is enough to limit the secondaries from opening and full throttle on the primary. There are no return springs on the progressive linkage. When attempting full throttle the spring tension actuates the throttle control rod off its detent at about half throttle and the carb link rod stops moving with the secondaries still closed even though there is pedal travel left. Anyone have some suggestions or illuminations?

57 Black Tbird 312/auto