Longtubes vs Shorty Headers for the HEMI: Which Makes More Power?

Header Basics: What They Replace

The factory Challenger uses cast iron exhaust manifolds — heavy, efficient at managing heat, but restrictive in terms of exhaust flow. Headers replace these manifolds with equal-length steel tubes that optimize exhaust scavenging — using the momentum and timing of exhaust pulses to help pull the next exhaust charge out of the cylinder.

The two main types are shorty headers (stock manifold length or slightly longer) and long-tube headers (significantly longer primary tubes that extend further down the car).

Shorty Headers

Shorty headers sit close to the engine — similar packaging to the factory manifolds — and typically run to the same collector location.

Power gains on 5.7L/6.4L HEMI: 8–15 WHP with a tune

Installation complexity: Moderate — some header bolts are tight but most shops can do it in 4–6 hours

Tune required: Yes — O2 sensor position changes require PCM calibration update

Check engine light: Often triggers without a tune due to O2 sensor repositioning

Emissions: Generally maintains catalytic converter function; some kits retain the stock cat location

Long-Tube Headers

Long-tube headers extend the primary tubes significantly further down the car before collecting. Proper equal-length tubes on a HEMI require custom routing around the steering and suspension.

Power gains on 5.7L/6.4L: 25–40 WHP with full exhaust + tune

Installation complexity: High — requires dropping the engine mounts on some applications, significant labor (8–12+ hours at a shop)

Tune required: Absolutely — the O2 sensors move to post-cat locations; without a tune this will throw codes and run poorly

Check engine light: Will throw codes without a tune for rear O2 sensors

Emissions: Requires high-flow cats at the new collector location or test pipes (see catalytic converter article)

The Power Difference Is Real

Long-tube headers on a HEMI consistently produce 15–25 more WHP than short-tube equivalents on the same car. This is because:

1. Primary tube length: Longer tubes optimize the exhaust scavenging pulse timing for mid-to-high RPM power
2. Equal length: Factory manifolds and shorty headers have unequal primary tube lengths; long tubes achieve true equal length for all cylinders
3. Reduced restriction: More tube volume before the collector reduces exhaust backpressure across a broader RPM range

Recommended Brands

Long-tube headers:

• Kooks (1-7/8" or 2" primary): The gold standard for HEMI applications. Excellent quality, great flow, well-tested with HEMI tuning
• American Racing Headers (ARH): Competitive with Kooks, slightly lower price point
• JBA Headers: Good quality, widely available

Shorty headers:

• Mopar Performance shorty headers: Direct fit, maintains O2 sensor location
• BBK Performance: Affordable option
• JBA shorty: Popular mid-range choice

Which Should You Choose?

Long-tubes if:

• You're building a performance car and want maximum naturally aspirated power
• You're also doing cam, intake, and tune — the system gains compound
• You can afford the installation cost and tune

Shorty headers if:

• Budget is a concern (cheaper headers + easier install)
• You want some improvement over stock manifolds without full system work
• Emissions compliance is critical and you don't want to disturb the cat location

For a serious build — cam, intake, exhaust, tune — long-tube headers are the only sensible choice. The 15–25 WHP difference compared to shortys compounds with every other modification.