I have never seen a DANA/Spicer diff under a '67-'72 Chevy truck, unless it has been changed, something I have considered because of the various ratios available. Every single truck that I have personally seen has an Eaton axle/diff. In reading other forums, I have seen mention of a 3.90 gear set for the Eatons, but it seems to be nothing but "rear end vaporware!" It may be that the assembly plants out West used one rear end while those in the East used another for shipping reasons or whatever. I'd love to find a DANA/Spicer 60 for my truck because a local supply house has gear sets on the shelf. It is my HO52 Eaton that I can't find anything taller than 4.11 for. Go figure!
Best wishes,
Les
