My2nd 69 442

Can anyone tell me what the STOCK steering input shaft spline count should be. I want to replace my Rag Joint but would like to have the correct part on hand prior to removing to old rag joint.
Rock Auto lists 3 different choices Either 25, 31 or 36 spline count
Thanks

My2nd 69 442

For anyone who may care the spline count for the rag joint on my Stock steering box is 13/16 shaft with 31 splines