pinion seal size?????

[photon]

My pinion seal is leaking and going to replace it this weekend.  The dana 60 under the back of my car came from a 68 mopar.  What pinion seal do I need for this dana?  I Went to my local parts store and i was given three choices of 7.25, 8.25, or 9.25.  I Have 354 gears.  Thanks for the advice.

[metallicareload99]

Should be a National part # 6808N

[John_Kunkel]

Your parts store is clueless, the Dana 60 is a 9 3/4".