Hi; I now have a 1954 3100 half ton. My first car was a 1954 Chevy. That car would go all day at 55 mph. It had a 4:11 rear end. My truck has a 3:90 I belive. I've seen notices to the effect that to go that fast in the truck for any length of time I should switch to a lower ratio differential. I'm confused - which is a normal state for me. How come the car would run at 55 with a 4:11 but I shouldn't go that fast for a long time in the truck with a 3:90?
Thanks.
Rich
