Aftermarket kick down cables

Hey guys last sunday i bought my first mopar!! A 1972 Plymouth duster with a mild built 318 727 tranny and a 8 3/4 rearend. Anyways i was trying to adjust the kickdown linkage but i could never get it to where i think it should be at if at light throttle it shifts from 1-2 at about 10 and 2-3 at about 17. So i was thinking about getting a aftermarket kickdown cable instead because ive read some good things about them. My main questions are what cable do you guys recommend? i know there is a couple different ones i was looking at the Lokar. Are they hard to install? And do i have to do anything different with the throttle cable? Any and all help is greatly appreciated! Thanks!