Need a replacement pin.

Thanks for posting. This is called a pivot bar. The actual length is not as important as the design of the pin that fits into the pivot shoe in the window track, and the distance between that pin and the center of the mounting hole(s) used. Start by looking at the 26-226. See if this matches what you need, or let us know if it differs in any fashion.

End view of the 26-226 pivot bar