Oil Leak Small block 360

I wonder if you getting confused with where the rear main seal goes
when you pulled the back most main cap off, there was a 2 piece seal in there
one piece went into the block ,around the crank, the other piece went into the cap (on the INSIDE, where the bearing is aswell)
that is the rear main seal
then when you installed your oil pan you used a 2 piece seal, two pieces that laid flat on the rail of the block and two round ones
the round one that lays on the OUTSIDE of the rear main cap is NOT your rear main seal, it is your oil pan seal