I have a 1949 Ford F1 pickup (Hope I can sneak in a Ford question). Is there a later differential with higher gear ratios to “speed” things up?
Low gears are a common issue for many early truck owners as most were used as tools to move stuff and rarely seen as a vehicle for general transportation. In 1949 Ford commonly used gear ratios of 4.27:1 and 3.92:1 on F1 pickups. These are gear ratios that can make modern highway driving difficult or even impossible.
Many convert these trucks over to a more modern 9-inch rear axle that offer a wider range of gear ratios. While the 1957 to 1972 F100 9-inch axle is a close fit, it will still require some modifications, which commonly include shock mounts and sometimes pinion yoke to reconnect the driveshaft.
Another option is to locate a 3:73 higher gear rear axle for the F-1 that was offered from 1948 to 1950. These are a little harder to locate but they’re out there.
Finally you could change the gears in your rear axle. There are sources that offer 3:54.1 rear axle ratio gear sets for your truck. If you’ve never done this though I would encourage you to get the hands-on assistance of someone who is familiar with these axles and how to properly setup the gears.