i have a 5.7 hemi with EFI and 727 in my dart and my method was to use the the cable type (lokar) kickdown linkage, and fab a bracket for the throttle/kickdown.
Once I made a ample bracket, and I was sure the throttle pedal was getting full range of motion, (WOT) I attached a 2nd pin to the throttle cam for the the kickdown linkage.
For proper actuation/travel of the kickdown lever I measured that 2nd pin travel from idle to WOT, (like cable pull distance) and then measured the travel of the transmission lever at the attachment hole. In order to get proper travel at the trans I ended up drilling a hole about 1/2" closer to the transmission on the lever to match my Pin travel at the throttlebody...
works great, and the lokar kit is adjustable for fine tuning...
JOE