It is possible to increase the towing capacity of a Chevrolet 454 truck engine by upgrading the power output of the engine with tuning and modifications. However, it is important to make sure that the upgraded engine is installed in a truck that is structurally capable of towing the desired load and fitted with the correct towing equipment.
The towing capacity of the Chevrolet 454 truck engine is mostly determined by peak torque rather than horsepower, so modifications that are biased toward improving torque output are desirable for improving towing capacity. Free-flow intake and exhaust systems improve engine power by providing more clean air and a more efficient exhaust for the engine. Intake and exhaust modifications are among the most common performance upgrades for any car or truck engine since they are relatively easy to install and provide good gains in power for their price.
Modifying the Engine Control Unit software of a modern 454 engine for more power output is also an inexpensive and effective option; many companies sell modified version of this software, so little programming or tuning experience is required to perform this upgrade. More complex operations such as upgrading the engine's cylinder heads and polishing the cylinders can yield towing performance gains, but these modifications are often expensive.