440 rear main seal... thoughts

You say you "clocked" the seal. I assume you did the old "trick" of misaligning the seal joints with the block to retainer joints? I never do that. I put it in as designed, put a dab of RTV on either end of the seal, put RTV on the retainer and assemble. Everyone I know whose tried the misalign trick has had a leak. I just don't do it. I hope it works.