Re: Unidentified 66 HiPo C4 Transmission part
That goes in the pump (I'd have to check a TransGo instruction sheet to see which passage) and it used to prevent converter "ballooning" . You could check an online instruction sheet to see which passage I'm talking about. If that was in their I'll bet someone added a shift kit to the valve body at some time. The sad part is all the springs were IDENTICAL and the separator plate was already drilled to size. All of the Trans Go parts for the 'Green dot" valve bodies are sourced from the K code Ford valve body except that converter 'bullet" you are asking about.
Experimental Ford parts collector.