70 B-body wiper pivot spline size

[Camoyj]

Does anyone know the 68-70 B-body wiper pivot spline size? I used a cable drive wiper system and it has a 5/8 splined stud for the wiper arms. I hope the stock B-body arms use the 5/8 splined stud so I can use them.
Thanks

 

[5.7 hemi]

Tape measure? That’ll tell ya the size.

 

[Camoyj]

Tape measure? That’ll tell ya the size.

I don't have any of the original pivots or wiper arms. That's why I need to know the size.