A '59 w/261? Not sure, but I had a 62 C60 w/261 5spd + 2spd + 20" rear (not an overdrive tranny, just shorter throws between gears.
I had a long talk with the previous owner before deciding to trailer mine home 55 mph would get the motor spinning along pretty well. It would hit 60mph for short bursts . . . not fast enough for a 150 mile ride home for me.
