Will not KICKDOWN (340 6 PAK, 727)

It's okay the way he's got it mounted, if you go towards the rear the spring attaches to the linkage and will do the same thing. As Fishy68 stated the spring just needs to be strong enough to hold the linkage at zero throttle.
I'm still making the fine adjustments to mine, I'm using a 78 318 and 904 combo and the adjustment is a little different. Adjustment on mine is at the tranny arm, the rod is held in place with a set screw (bolt). I'm having trouble getting the shifts correct, ran out of shaft and had to weld a couple inch piece of bar stock on the end. Move the rod enough to get the arm from the tranny all the way back at full throttle and it's now holding in 1st just a little too long but holding 2nd way too long at part throttle acceleration. Will try tomorrow and back it off about an 1/8" and go from there... It is a pain because you have to pull it up on ramps to get under the car to make adjustments with the 78 set up. I have a feeling I my end up with an aftermarket set up.