I just returned from my trip to Connecticut, and my '66 C-10 with the original 250 cruised along at 60-65 mph, and got about 17 mpg.
It may not be very fast, but it got me there and back safely. To top it off, the ride was very comfortable, even on those crappy Northeastern roads.
Whoever thinks that an old 1960's Chevrolet truck is unreliable and uncomfortable is full of dung.
