Question about 904 tranny kickdown band adjustment

It's finicky, and especially with a non-stock (and modified, at that) kickdown cable. Added to that is the fact that '65 904 transmission valve bodies do not have part-throttle kickdown, and it becomes an all-or-nothing situation; either it's right or it's not. And the consequences are severe if it's not.
Me? I'd place a parts wanted ad here and try to get the correct kickdown linkage for your car, then adjust it according to your FSM (you do have one, right? And I don't mean a Chilton/Motor/Haynes manual either- get the honest to goodness Chrysler FSM).