Here's what I found out.
I have a Scout TC 146 1980 Scout Dana 300 with 13 teeth.
Part # 890182 The speedo cable is on the pass side.
I took a Gear out of a Jeep Dana 20 15 teeth.
Part #890206 The Speedo cable is on the drivers side.
Both gear look the same. But the Jeep teeth turn one...