Even using the FACTORY setup , for instance my 1 piece kickdown rod/linkage on my 71 Bee


Like the initial poster says , pulled forward all the way on the kickdown lever down on the trans per Chrysler tech using a spring and a tool straight from all the manuals and adjust from there by the carb linkage or how Hotrod and A & A Trans mention this with the kickdown lever down by the trans


http://www.hotrod.com/articles/the-lowdown-on-stock-torqueflite-kick-down-linkage/

As the kick-down linkage/cable pushes the kick-down lever rearward, it increases line pressure inside the trans and initiates a downshift. “If you adjust the cable so the lever is at the front of its travel range at idle, the line pressure will not increase properly as the throttle increases,” Jason Muckala of Motech Performance explains. “This makes the trans shift too early, and it can cause the clutches to slip and destroy the transmission. I’ve seen people install springs to hold the lever forward, but it’s not supposed to stay in that position at idle.” This photo shows the lever full forward; in this portion of the lever’s arc you can feel no pushback from the lever, an indication that no increase in line pressure is occurring.




Somewhere in this range of the lever’s arc, you can feel a slight resistance from the lever’s internal spring. This is where the line pressure begins to rise, ultimately causing a downshift. Properly dialing in the lever’s range of motion is critical to shift performance and transmission longevity. Says Jason:

“For the FIRST HALF OF IT'S TRAVEL RANGE, there is very little resistance and the LEVER DOES NOTHING. AT THE HALFWAY POINT, you can feel where it starts to hit the valve inside the trans, AND THATS'S THE POSITION THE LEVER MUST BE IN AT IDLE.”



At WOT, the kick-down lever should be positioned at the end of its range of travel. This ensures accurate shift points and a proper increase in line pressure. Factory kick-down linkage setups can create scenarios where the kick-down lever will not move all the way back at WOT, or scenarios where the lever moves all the way back and hits a hard stop before WOT. Now you can begin to understand why it’s important for the bellcrank on the throttle shaft to move in perfect sync with the kickdown lever on the trans in a 1:1 ratio.