pinion seal on dodge 7.25

[agrevbuzz]

I have just finished changing the oil on a "new" differential for my '76 dart. While I was prepping to take the old one out and replace, I noticed oil leaking from the front of the pumpkin....Pinion Seal.

Does anyone know what size the nut is that attaches the yoke to the pinion shaft?

 

[72BlueSwinger]

Should be about 1 1/4 inch. I'm not totally positive on that.