Congradulations! Nice to see that you were able to isolate & repair the issue.

As far the the ATF fluid- I do know that Ford type F is more sticky than Dexron- in my younger days when I played with cars- whenever you put a shift kit in a GM model- the instructions always said to replace the Dextron with Type F for improved shift performance.

Also- I have a parts book for your truck so if you ever need part numbers feel free to contact me