Living with 3.91's

Man those 340's must have been great to take up to 7000 rpms once the motor was blue printed.
They were!!! Ran 4.89's in my old 340 Swinger on the street back in the early '70s - fun on the street and the track, but couldn't take it on the freeway with those gears.
Currently building another '69 Dart with a 360/727 combo and will have 2 chunks: 1 with a freeway gear for road trip car shows and events and 1 with 3.73's for local cruise nights and some track times.