Decoding info on a 12-bolt posi from an A Body
 

The rear has same dimensions as a 68-72 Chevelle. It is an original 3.73 posi. which had the boxed control arms and stabilizer. The info on the axle tube is RC G822K, the casting # is 3959038 with a date code of H148. Thew brake drums are a little different from my chevelle. I don't have any books other than Chevrolet, can anyone help me out? This rear is for sale!