I have just put my 1951 1 Ton on the road and it has a 1971 4:10 ratio gearset in the rearend. With the stock 216, it cruises along at 50 mph although hills can be a challenge. It will max out at about 60 on the flats. What this means to me is a ratio any higher than the 4:10 would probably not help because it just wouldn't have the power to push the truck any faster.
