Truck towing question

Yeah the new trucks have improved but due to od trans and less gear ratio

That it the reason tow ratings for older trucks are different. The newer trucks are designed for highway use and basic transportation

The old trucks were designed to WORK

My 1967 Ford F100 custom cab 300 straight 6 3 on the tree got 11 mpg on its best day. But it could pull a load. Wasn't fast, but it would work

Brother had a 1967 Dodge d100 had a slant 6 these trucks were just trucks, nothing fancy, probably have 3.73 or 4.10 gears in a 68-72 truck

If you can find a big block will probably be a 200 series

If you are looking for a 68-72 it will be a truck