NickDash

I just recently aquired a 1985 Camaro z28. It has just over 53k miles and I am unsure of the previous maintenance record. I would like to do a trans and rearend service but I am getting mixed feeback and whether to do it or not. The fluid is a little dark but not too bad and the level is fine. I have a pic but I dont think I can post it yet since this is my first post. Some feeback would be appreciated.

edit talking about trans service not rear