I am just curious how the big trucks like the 6400 size and buses up through the 1940s early 50s got around hauling heavy loads being limited in engine horsepower. I know my 6400 with a good running 235 is underpowered when under a load. Did the older trannys/rearends have lower gearing?? My 53 6400 has a 1955 4 speed in it. I know that 235 will pull way down when climbing hills with a load on it. Did they have lower gearing?
