I have never seen anybody put a rope seal in with the crank still in place and not have it leak!!!!
But there is good news there is a replacement that is a lip seal design like a standard small block.
The bad news is i just can not remember for the life of me where i got them???? I still have one left and if you cannot find one i'll sell it to you if you need it. I'll try and look to see if i can find where i bought it from.....