I have a 57 selector trans apart that apparently needs a new cluster gear. The one I took out has 21, 17 and 16 teeth. it should be a gm part number 1189189 gp. 4.421 according to my United Delco transmission parts book.
I have located one on that auction site with the same part number but it has 20, 17 and 16 teeth. All the other dimensions are the same.
This tranny has been around the horn so to speak so I cannot be sure that it has not been modified in it's previous life.
Q
Will this work in this tranny or will the input gear need to be changed as well??