Hard to see clearly but it looks pretty ragged , I doubt that's factory, sorry If I'm no help.Seen a lot of A-body's over the years but I've never seen a hole there. People do a lot of weird things sometimes just out of laziness.My last Dart had holes drilled through the trans tunnel . I guess some out of shape mechanic could not reach the 4 bolts holding the transmission to the engine so He peeled back the carpet and drilled holes for a long extension!