How to increase HP on a 350 Chevy?
The Chevy 350 can gain horsepower through bolt-on upgrades, cam and head work, proper tuning, and, for the bold, forced induction. Results depend on the current engine and how it's built.
This article outlines practical routes to increase power, from budget-friendly upgrades to more ambitious builds. It covers carbureted and EFI setups, and it discusses reliability, emissions, and how to plan a build that fits your goals and budget.
Assessing your starting point
Before spending money, evaluate the engine’s current health and your performance goals. A clear baseline helps you choose upgrades that actually deliver the power you want, without compromising reliability.
What to inspect
Check cylinder compression, leak-down, and cam timing; inspect the ignition system, fuel delivery, cooling system, and oil health. Document current carburetion or EFI setup, exhaust condition, and any signs of leaks or overheating. Understanding the baseline prevents mismatched parts and unnecessary costs.
Bolt-on upgrades for modest gains
These upgrades are generally reversible and suited for street use. They typically offer incremental horsepower improvements with lower risk and simpler tuning compared with internal changes.
- Exhaust system upgrade: install headers and a freer-flowing exhaust to reduce backpressure and improve scavenging.
- Intake and airflow: upgrade to a performance intake or a cold-air intake designed for small-block Chevys to improve airflow into the engine.
- Fuel delivery and carburation: replace or upgrade to a 4-barrel carburetor or a modern EFI throttle-body/intake for more precise fueling.
- Ignition system: upgrade to a hotter coil, an updated distributor/ignition module, and better wires/plugs to improve spark energy and consistency.
- Fuel pressure and tuning: ensure fuel pressure is correct for the chosen intake/cuel and perform basic timing/tuning adjustments after parts install.
Expect modest gains from these bolt-ons, often in the range of a few to a few dozen horsepower depending on the combination and the engine’s starting condition.
Head and cam upgrades for bigger gains
For substantial horsepower increases, head work and cam swaps unlock more airflow and a broader power band—but they demand careful matching of compression, fueling, and tuning to avoid driveability issues.
- Camshaft and valve train: a more aggressive cam with higher duration and lift, paired with appropriate springs and pushrods to maintain reliability and proper valve control.
- Cylinder heads: ported or upgraded heads (including aluminum options) with larger valves and optimized combustion chambers to improve flow and compression management.
- Intake and exhaust matching: select an intake manifold and exhaust components that align with the new cam and head setup, and tune the system accordingly.
These upgrades can significantly boost horsepower, but gains depend on how well the components are matched (cam timing, compression, heads, and fuel delivery) and on a proper tune. Poor matching can reduce low-end torque or cause detonation on pump gas.
Fuel, ignition, and tuning considerations
Tuning is where much of the horsepower is realized. Proper fueling, ignition timing, and air-fuel calibration determine how effectively the hardware translates into real-world power.
- Compression and octane: higher compression or more aggressive timing often requires higher-octane fuel to prevent knock, especially with performance cams.
- Ignition timing: adjust timing curves to suit the cam and compression; a well-matched distributor curve improves both power and drivability.
- Fuel delivery and monitoring: ensure the fuel system keeps up with the demand (pumps, regulators, lines, injectors or carb jets) and use a wideband O2 sensor or data logging to optimize air-fuel ratios.
With proper tuning, you can unlock most of the power potential from your hardware while maintaining reliability and fuel economy characteristics appropriate for street use.
Forced induction and big-bore options
For the highest power potential from a 350, forced induction or larger internal components are the most impactful paths, but they also require substantial planning, funds, and professional tuning.
- Supercharging: a roots or twin-screw setup can provide strong, linear boost and relatively modest lag, but it increases strains on internals and requires cooling upgrades.
- Turbocharging: a properly sized turbo delivers significant power, often with excellent efficiency, but demands advanced fueling, intercooling, and robust exhaust and oiling systems.
- Internal and fueling upgrades: forged pistons and rods, upgraded cam bearings and oiling, higher-flow fuel delivery, and a capable cooling system are commonly needed to handle boost safely.
Forced induction delivers dramatic horsepower gains, but it also increases maintenance, heat management needs, and the importance of professional tuning and emissions compliance. Expect a much higher total cost and a longer build timeline.
Choosing a plan and budgeting for your build
A clear plan helps balance ambition with practicality. Start with your target use (street, weekend warrior, or drag/track), then allocate funds to the core areas first.
- Budget bolt-ons (entry-level): parts and labor for exhaust, intake, and ignition upgrades.
- Moderate builds: cam and head work plus a matching intake/EFI or carb setup, plus professional tuning.
- High-performance builds: forced induction and forged internal components, extensive tuning, and upgraded supporting systems.
Setting realistic goals and layering upgrades in stages can yield the best long-term reliability and satisfaction, while staying aligned with emissions rules and vehicle use.
Installation considerations and reliability
Whether you DIY or hire a shop, compatibility with transmission, cooling, and fuel systems matters. Use quality gaskets, hardware, and torque specifications, and consider professional assistance for internal upgrades to ensure reliability and longevity.
Beyond installation, plan for ongoing maintenance and monitoring. Upgraded power means higher heat loads, so ensure cooling capacity is adequate, maintain oil pressure, and periodically verify timing and fuel trims under real-world driving conditions.
Summary
Increasing horsepower on a Chevy 350 is a staged process: start with bolt-ons for modest gains, move to cam and head work for bigger gains, refine with thoughtful tuning, and consider forced induction only if you have the budget, time, and commitment to a thorough build. Align your goals with the engine’s condition, fuel, and emissions requirements to achieve reliable, repeatable power without sacrificing driveability.
How to get the most power out of a 350?
Replacing the 2G with a Q-Jet and intake alone can be worth 25-30 hp. Toss in a mild cam and cylinder head upgrade and the power gains really start to add up. Though this power level would easily be served by a set of ported stock or Vortec heads, we stepped up to a set of as-cast Pro Action aluminum heads from RHS.
How much HP can you get out of a Chevy 350?
That said, while a stock 350 Chevy may only have 200 or so hp, you can easily make 300 horsepower with a 350 Chevy budget build and upwards of 600 horsepower with a Chevy 350 max hp build with the right combination of parts used.
Can you get 400hp out of a 350?
Remember that this will also require a Vortec style intake gasket. The combination of the heads, Xtreme Energy cam, Performer RPM manifold, 750 cfm carburetor, and headers will push your 350 into the 410 to 420 hp range — again assuming the rings are in decent shape.
What is the cheapest way to add horsepower?
A performance air filter or cold air intake is one of the cheapest ways to increase horsepower. What intake adds the most horsepower? A cold air intake usually adds the most horsepower among intake options. Can you add a turbo to any car?
