I agree with above. Most 1/2 ton pickup trucks have springs comparable to those on a Crown Victoria. The maximum tow suspensions are available, but expensive. Most are special ordered.
A 1/2 ton truck will tow a heavier travel trailer than a fifth wheel trailer due to their having 10-12% of the trailer weight on the bumper vs. 20-23% of the trailer weight in the middle of the pickup box.
The only 1/2 ton truck that approaches the weight carrying capability of a 3/4 ton truck is the 2015 (aluminum) Ford F150 with the maximum tow package. They're substantially beefier than any of the competitive 1/2 ton trucks.