a904 problem

hello all, so got my car running and driving recently 65 barracuda 318\904\stockconverter, my i put a valve body in it that has a stg 3 shift kit in it that worked in another 904, for some reason it would only shift with the line pressure lever completely disconnected, it would never shift with the lever cranked back a little, half way or wide open

the trans has all new clutches, bands and seals, air checked everything is fine,this is my 5th torqueflite ive rebuilt, but anyways, the valvebody ive ran in my truck (75d100 318\727)
for a few months and it worked amazing along with a friends car previous to my truck, got another valvebody for that and out came the modified valvebody, so i already knew the valvebody worked fine, but for some reason in it wont shift with the line pressure lever opened on this trans

any suggestions would be grateful thanks