Another thing that people don't look at is capability through out the years as well. What these trucks are able to tow these days would have required a big medium duty truck with a much bigger displacement back then. A 1992 Ram D350 DRW CTD had a tow rating of only 12,000 lbs. A 1992 Ford F350 DRW diesel had a tow rating of just 10,000 lbs. To tow a common 14,000 5th wheel would have required an F650/F600 class truck back then which our 3/4 tons can easily do today and get much better fuel mileage than those things did doing it.