I'm not a grandpa yet, but my first car was a 67 Impala Supersport with a powerglide behind the good old 283. As I recall it would move pretty good from standing still, but 2nd gear came so late that the engine was really whining before it dropped into high gear. Then the RPMs dropped something fierce and the acceleration basically took a dive. Once it got up to 60 you could keep it accelerating a long time, the motor would push it a lot faster than that old car should have gone. It seems to me that if I punched it good at 55 or 60 it would drop down into first (passing gear?), but practically speaking I can't believe my own memory - the motor should have been completely wound out at that speed in first.
It might have been a dependable tranny, but I wouldn't want to drive one now.
Karl

It may not be the easy way, but it is the Cowboy Way - Ranger Doug
Beware of the stories you read or tell; subtly, at night, beneath the waters of consciousness, they are altering your world. - Ben Okri
1953 Chevy 3100
1960 Volvo PV 544
1941 Chevrolet Special Deluxe