Hey everyone. This is what I know...I have a Chevy rear end with a casting number that is: 3896839. I have narrowed it down to one of 2 vehicles that it could belong to but would really like to know for sure. My thoughts are that it could go to a SS Chevy II, or a 70's truck/blazer. It is 58" from the inside and about 64" from the far outside, and it is a 12 bolt. Not sure about the year either. Any info that you can send my way would be very appreciated.