Took my 85 300D to my mechanic after changing the compressor, lower suction line, evaporator, and the drier. I put the seals in the compressor and tightened them. He vacuumed it down and found a leak at the compressor, so he tightened them. Later after a month I came home and heard a sound, checked it out and it was leaking at the right line/seal of the compressor. When I tried to tighten it more it vented! I loosened it up and it stopped except for the original sound. I disconnected the compressor to avoid it seizing up. Do you think it is stripped or maybe I installed the green seal from Delphi backwards??? Please help, need to take to the mechanic and want to have an idea of what is wrong!

One seal was green. What about the other one?

It came with a red one but the compressor I bought new didnt need the red one. I believe the other one was a fat seal like the ones one the lines?? I know it sounds dumb I cant remember

For some reason, the compressors often don't come with the correct seals. You probably needed a gold one ( NAPA part #TEM 407279) on the suction side. If you used a standard o-ring, no wonder it leaks.