Distributor O ring/ gasket part #

This may sound kinda odd, but I use one thin (approx 20 thou) Oring on the distributor ledge where it contacts the block instead of counting on the one that goes down the hole.
Perfect and dry as a bone, because it pinches the oring between the distributor and the block.
Of course I leave the other one in the groove anyway, but it would make zero difference if it was there or not.

You know, that corner in the aluminum right above the existing oring groove.
Learned that trick about a bazillion years ago.