Called Show Cars and found their 348 pan is actually built to 409 OEM spec, but has the dipstick on the 348 side. As a result, the pan is larger and too deep for my boating application.
It appears my only options are to refurb the existing one by hammering out the dent, or go out and find a used 348 oil pan. I'm going with refurbing the existing pan as the dent is not large and the pan seems ok otherwise.
Appreciate all the replies and suggestions on here!