Small U Joint Fine Spline Pinion Yoke.

Hello Demonracer, I want to say its for a 741 case as I changed a small yoke from a 741 cased 3.91 to my large u joint driveshaft
with a large joint yoke. Other than that,
I dont know how to tell the diffrence between the two. Maybe someone here can ID it?
HotRod20