smallblock flexplate

I have a 1975 dart 360 and would like to use my neutral balance convertor with this ext balance 360. Friend of mine has a flexplate, I haven't seen it but he had it behind a ext bal 340 or 360 he is not sure, been several years. The number on it is 10234. I can't seem to locate this number unless it was superseded to a newer number, any help would be great in knowing if this can be used behind my 360, thanks...