aFe Twisted Steel Headers — Nissan 350Z / Infiniti G35 3.5L V6

Twisted Steel headers for Nissan 350Z and Infiniti G35 3.5L V6

The aFe 48-36103 pair uses 1-5/8-inch 16-gauge 304 stainless tubing, hand TIG welding and 3-to-1 formed collectors for the listed 2003–2006 gasoline V6 3.5L applications. The guide requires cold-engine coolant draining and water/heater pipe removal but omits refill, bleeding and level procedures. Obtain the complete exact vehicle cooling-system restoration instructions and final heatshield disposition before work.

Key Features

• Selected aFe part 48-36103.
• 1-5/8-inch 16-gauge mandrel-bent 304 stainless tubing with hand TIG welds.
• 3-to-1 formed collectors; flange thickness remains unverified because the current manufacturer detail prints an unresolved 1-5/8-inch-thick flange claim.
• One right header 05-45941, one left header 05-45942, two bolts 03-50401 and two nuts 03-50400.
• Mark original head gasket positions and reuse original gaskets and head nuts as directed.
• Restore original O2 sensors, Y-pipe and bracket, water/heater pipes, intake, cover and other removed retained components.
• 9 hp/11 lb-ft is a manufacturer claim from a 2003 Nissan 350Z test; no selected dyno chart is linked.
• 16 hp/15 lb-ft requires the separately sold matching Y-pipe, not the header pair alone. Manufacturer states not CARB exempt with California restrictions.

Fitment

Only the listed 2003–2006 gasoline V6 3.5L applications are supported, with each trim’s exact year range below. The manufacturer names Infiniti G35 Coupe/Sedan and Nissan 350Z; shared displacement does not approve later years or other engines. The independent exact-MPN table supports all eight original scopes and adds 350Z Touring 2003–2006. Infiniti make-name capitalization does not create a new application.

Specifications

What's Included

• The 48-36103 kit includes one right 05-45941 and one left 05-45942 header.
• Two bolts 03-50401 and two nuts 03-50400; verify intended hardware allocation against current manufacturer instructions.
• Original head gaskets/nuts and specified original sensors, pipes, Y-pipe, bracket and vehicle components are reused. New head gaskets, coolant, the separate matching Y-pipe, intake filter and coupler are not established as supplied.

About aFe Power

aFe Power develops application-specific intake, filtration, exhaust, cooling, tuning, suspension, drivetrain, and truck-performance components supported by product testing and documented installation requirements.

Related Parts

• Exact manufacturer header pair and qualified performance claims
• Complete selected guide and formal bill
• Full exact-MPN named application table
• Shop headers and manifolds

FAQ

It is the selected 304 stainless header pair for the listed Nissan 350Z and Infiniti G35 gasoline V6 3.5L configurations, with two bolts and two nuts.

The current manufacturer detail prints that claim, but it is unresolved and matches the tubing diameter. Exact flange thickness is unverified; confirm with aFe rather than assuming a different dimension.

Yes. The selected guide specifies draining coolant on a cold engine away from drive belts, then removing both water and heater pipes and later restoring those pipes.

No. It provides no refill, bleeding, level or final cooling-system check procedure. Obtain exact aFe/current vehicle cooling-system service instructions before work and complete proper restoration before operation.

Both are removed, but the guide gives no final disposition. Confirm the correct final shielding arrangement before work; the omission does not establish permission to leave required shielding absent.

No. The manufacturer attributes that higher claim to combining headers with separate Y-pipe 48-36104-YC. The standalone 9 hp/11 lb-ft claim names a 2003 Nissan 350Z test, without a linked selected dyno chart.

No new gaskets or Y-pipe appear in the formal bill. Mark original head gasket positions and reuse the original gaskets and nuts as directed; the matching Y-pipe is separately sold.

No numerical torque is printed in the selected guide. Use exact vehicle fastener service specifications and recheck all clamps, bolts and nuts after 50–100 miles.

Installation Instructions

1. Confirm aFe 48-36103 against the exact vehicle and installed equipment. Inventory the actual components and follow the selected manufacturer instructions and current vehicle service requirements.
2. Confirm exact application and inventory the formal kit. Obtain current aFe clarification of flange thickness, supplied hardware allocation, final manifold heatshield disposition and the complete exact vehicle coolant restoration procedure before work. Cool and safely support the vehicle/exhaust.
3. Follow the selected battery disconnection instruction using the exact vehicle service procedure; no terminal order is printed. Remove retained tower bar, engine cover, original intake and undercover as directed. Drain coolant only on a cold engine, avoiding drive belts, then remove both water and heater pipes.
4. Label and remove the specified O2 sensors from both manifold and Y-pipe locations, retain the Y-pipe/bracket and original head hardware, and remove both manifold heatshields. Mark original head gasket positions and reuse original gaskets/nuts when installing the selected left/right headers under exact vehicle fastener specifications.
5. Restore both water and heater pipes, original O2 sensors and harness routing, Y-pipe and bracket, intake, engine cover, tower bar, undercover and battery connection as directed. Complete confirmed final shielding and the full exact cooling-system refill/bleed/level/check procedure before operation; those cooling completion details are absent from this selected sheet.
6. Check all work, routing and safe clearances under the exact manufacturer/vehicle requirements. No numerical torque is borrowed from another product. Recheck all clamps, bolts and nuts after 50–100 miles.

California Proposition 65 warning: this product can expose you to chemicals known to the State of California to cause cancer and reproductive harm.