I got a differential from what I think was a 1983 500SEC to swap into my 1985 300TD. I want to do seals (pinion and axle) for the SEC diff before I install it in the TD. Trouble is now I am wondering if the car I got it from at the Pick N Pull was a 380SEC that a coke-snorting Miami Vice guy put a 500SEC badge on. Can anyone with parts lookup capability tell me if it matters? I'm guessing the 1983 380SEC and the 1983 500SEC have the same diff, but I don't know for sure. Thanks!!!!