I`m guessing the old spring is broken and/or fallen away from where its supposed to be. So you could compare the spring kit you got and the one you need. It can`t be that hard to figure out ,unless its the wrong spring.
~ BD. "You won't find me in an old folks home" Pioneer Florida Cracker 1958 Apache Stepside 1958 Apache 1/2 ton Panel 1959 Apache 1/2 ton Panel