I decided to just buy new pan gaskets (2) from Advance Auto which are a black rubber type and made by Felpro. I did get new duraprene ones from CK Performance (free replacements since the trans leaked fluid out of the pan from day one
) but since the gorilla shippers decided to fold the box in half and smash it all to hell I didn't trust even using them. To be honest, I think the duraprene ones are garbage especially if you have a stock pan. Before I installed the new gaskets, I decided to try and get the pan as flat as possible (something that seems was never done from what I can tell before CK installed the ~30~ year old pan). Both front corners were bent which explains why I had such a bad leak from day one. I took my time to get it back perfectly FLAT and got the pan installed using the "better to me" gaskets from Felpro. No leaks now
I also pulled the electrical plug housing and cleaned everything real good and put a small bead of black RTV around it just in case the O-ring decided it didn't want to do it's job again. That leak is now fixed as well
Now after spending all this money on a transmission, I can finally DRIVE my car without leaving puddles everywhere I park and hopefully find that everything internally is working as it should be. I did notice a few tiny metallic flakes in the pan already, which I hope is 'normal' for a rebuilt transmission(?)