Rear Main seal leaks

Hi all.
New on this site.
I would like to address a problem.
I just rebuilt a 360 cubic inch v8 by myself and all was well up until I changed my oil after 500 miles from my running in oil to a normal semi synthetic oil 10w 50. I have seem to have developed a rear main oil leak. It seems to not leak while I am driving since there is no oil stain along the transmission pan. All seems to be dry, but when I stop for the night after a drive you will see maybe four to five drops of oil (it comes out of the bellhousing weep hole on the bottom) on the garage floor. I don't know if the oil chage provoked it or its just coincidence this leak has started. I installed a "ROPE" seal. I was very reluctant to use this type of seal. I have only installed rubber ones before. I did my best to install it very carefully, but not carefully enough.
I am just wondering since this is still very new can the seal be still bedding in?
Initially it was good. Is there something I could do about it? The only mistake I did was when I refilled the sump with new oill, I overfilled it by about one litre (almost two quarts). I drained it back since then but did not help.
Can anyone help?