904 problems

Hi guys was wondering if any of you guys have ever ran in to this, I have a 904 in my duster behind a healthy small block that is skipping 2nd gear, will go right from 1st to 3rd, if you manually pull in to 2nd it will go to a neutral like state unless slow enough will go to 1st, I was thinking maybe a valve body issue but not sure, I am a mechanic and know a bit but not a ton about automatics