I have 2 10 bolt rear diffs out of Chevy G20 vans and one 12 bolt out of a 1977 G20, more high performance. Gear ratios are unknown and probably around the 3.08 range but if interested I can get the ratios for you. All of them were driven to my shop from 100's of miles away but still would need new oil seals and cleaned up. I can blast and paint them and make sure everything is ok and ship them as a crate axle if wanted. $200 for the 10 bolts and $400 for the 12 bolt. If you want them blasted, painted,, and gone through we can talk about the extra cost for that. The 12 bolt is kind of a rare find.