8.4 x 1 tap

[Brooks803]

After reading through the ads I saw a couple people looking for specific taps or dies. I went through my assortment of stuff and didn't have what they were looking for, but I came across an 8.4 x 1 tap and I can't remember for the life of me what it was for !

Any ideas? Thanks in advance!

 

[BigShed]

Jr Gent II front section

 

[mredburn]

some of the Sierra transmissions, a couple of the other front ends as well.