Many times what was installed as a scupper in the boat ends up being used to pass spring lines .
If this is the case , be sure to purchase scuppers that are very very well rounded , inside and out, and large enough for a simple eye splice and 2 lines to pass.
This will usually require a larger opening cut to make the scupper fit.
After trimming the hole , cover the scupper wit 2 layers of aluminum foil and use filled epoxy to make them sit really tight.
Clean them up and use thru bolts , as in a serge the loads can be high.