Driveshaft question

Spacegrass said
On a 1973 Dart Swinger Special with a 318/904 and an 8 3/4 rear, would the driveshaft length be

Was this combo made?? Special order only maybe?? That's a heavy rear for light duty trans.... other folks here will know better than me, but I'd say thats not a likely combo, until people started setting them up that way themselves.