I'm just running the Dexron III that the big orange sticker on the site of the trans says to use.....
As I noted before, the noise seems to get more noticeable once the car has warmed up, so I was wondering if it had to do with the oil getting warmed up and thinner....
No harm in swapping out the fluid and see what it does....
This the one you are talking about?
https://www.summitracing.com/parts/red-58404