What options for O/D behind a S/6?

lots of arguments on here bout slant mileage. I've had them: feather duster auto ( yes they made them), 70-3 dusters, 4 speed OD, autos, old engines, rebuilt ones, all country driving ( not trying to stay alive on the Ca freeway!!) the non feather car, 4 spd OD got 30 ( true), the feather with well used engine got around 25, others got low 20's.
personally, I've grown to like the oddball slants, yea I still love any V8 too!!!
for some reason, some of us like the goofy typewriter pushbutton!!?? LOL