Chevy LS1 Intake Manifold Torque Sequence Diagram
LS1 intake torque guide comparing the stock composite 5/10 N-m procedure with Holley/Weiand aluminum 16 lb-ft hardware and a verified ten-bolt diagram.
For a stock-type 2002 Corvette LS1/LS6 composite intake, GM service information specifies all ten intake bolts in sequence to 5 N-m (44 in-lb), then all ten again to 10 N-m (89 in-lb). Do not apply that value automatically to an aluminum aftermarket manifold. Holley/Weiand P/N 300-111 uses supplied M6 x 1 x 90 socket-head screws and washers with anti-seize, tightened to 16 lb-ft in its illustrated order. In that Holley figure, viewed with the throttle-body/front end at left, the upper row is 10-6-2-4-8 and the lower row is 7-3-1-5-9; tightening order is numerical 1 through 10.
An LS1 intake does not use the high torque associated with a traditional Gen I cast manifold. The production LS1/LS6 assembly is composite, seals each cathedral port with a molded elastomer seal and uses ten small vertical fasteners. GM's two light passes are intended to seat those seals without distorting the plastic shell or pulling its inserts.
Aftermarket aluminum intakes can use the same head pattern while changing almost everything that controls clamp load. Holley/Weiand's P/N 300-111 instruction specifies its own longer M6 socket-head screws, flat washers, anti-seize and 16 lb-ft. Applying 16 lb-ft to a stock plastic intake—or stopping a Weiand assembly at the stock 89 in-lb—would ignore the hardware each manufacturer engineered.
The correct workflow therefore starts with manifold identification, not the engine badge. Photograph hose and harness routing, verify LS1/LS6 cathedral-port seals, inspect the knock-sensor/valley area for trapped debris and keep fuel-system safety central. Then choose either the production GM branch or the exact aftermarket instruction from beginning to end.
Interactive Holley/Weiand LS1 ten-bolt sequence
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Verified P/N 300-111 figure with the throttle-body/front end at left: upper row 10-6-2-4-8; lower row 7-3-1-5-9. Select 1 through 10 in order. Use the GM figure for a stock manifold if its orientation differs.
Chevy Ls1 Intake Manifold Torque Sequence Diagram
| APPLICATION / ITEM | SPECIFICATION | NOTES |
|---|---|---|
| Stock LS1/LS6 first pass | 5 N-m / 44 in-lb | All ten in GM sequence |
| Stock LS1/LS6 final pass | 10 N-m / 89 in-lb | Production composite intake |
| Holley/Weiand 300-111 | 16 lb-ft / about 22 N-m | Supplied M6 screws, washers and anti-seize |
| Main fastener count | 10 | Five along each cylinder-head rail |
| Holley supplied screws | M6 x 1 x 90 | Socket-head cap screws with washers |
| Port-seal family | LS1/LS6 individual seals | Verify exact manifold and gasket part number |
The stock composite and Holley aluminum procedures share a ten-position center-out pattern but not the same fastener, friction condition or final torque. The interactive map is transcribed from Holley's LS1 manifold instructions and is labeled accordingly. For an original GM intake, use the exact Corvette, Camaro/Firebird or swapped-engine service manual to confirm the same position orientation and two production stages.
How to use this specification correctly
- 01
Decode the engine and identify the installed manifold by casting or part number. Confirm a ten-bolt cathedral-port LS1/LS6-style flange; do not use this page for LS3/L92 rectangular-port heads or a manifold with a different instruction sheet.
- 02
Relieve fuel pressure by the vehicle service procedure, disconnect the battery and work in a ventilated area away from ignition sources. Label the injector, MAP, TPS/IAC or electronic-throttle, EVAP, brake-booster and PCV connections before disassembly.
- 03
Remove the fuel rail and injectors only as the application manual directs. Cap open fuel lines, protect injector O-rings and keep dirt out of the ports. Disconnect coolant/EGR hardware where fitted without forcing aged plastic fittings.
- 04
Loosen the ten intake bolts progressively rather than bending one end of the manifold upward. Lift the intake clear, immediately cover all eight ports and vacuum debris from the valley before any cleaning work.
- 05
Inspect the manifold shell or aluminum casting, bolt bosses, injector seats, MAP port and vacuum fittings. Replace flattened, cut, swollen or hardened individual port seals; never try to recover compression with added torque.
- 06
Clean the cylinder-head sealing tracks without scratching aluminum. For a stock composite intake, follow GM's seal installation method. For Holley/Weiand P/N 300-111, follow its specified Ultrablue gasket-retention instruction and required coolant-line modifications for early LS1 versus LS6-style valley plumbing.
- 07
Lower the manifold into place without rolling the port seals. Connect any rear vacuum lines that become inaccessible after final positioning, then confirm the manifold sits evenly and all ten holes align before inserting bolts.
- 08
Install the exact fastener set and friction treatment. Stock production hardware follows the GM manual; the cited Holley/Weiand manifold uses supplied M6 x 1 x 90 screws and washers with anti-seize. Hand-start every fastener and stop if one binds or bottoms.
- 09
Orient the physical sequence. For stock LS1/LS6 service, tighten all ten to 5 N-m and repeat all ten at 10 N-m. For the cited Holley/Weiand manifold, follow its 1-through-10 figure and tighten the supplied anti-seized hardware to 16 lb-ft—never combine the two branches.
- 10
Reinstall injectors with properly lubricated undamaged O-rings, secure the fuel rail, reconnect sensors, EVAP, PCV and brake-booster lines, then pressurize the fuel system before starting. Check for fuel, vacuum and coolant leaks and review idle/fuel-trim data after warm-up.
Stock composite LS1 torque stages
The cited 2002 Corvette LS1/LS6 service procedure uses 5 N-m (44 in-lb) for the first pass and 10 N-m (89 in-lb) for the final pass. Each pass follows all ten positions in sequence. These are inch-pound values; setting a foot-pound wrench to 89 would be catastrophic.
Use a calibrated low-range inch-pound wrench whose working range includes 44 and 89 in-lb. A large click wrench near the bottom of its scale may not control this light joint well. Smooth pulls and an uninterrupted sequence matter more than repeatedly checking an already seated composite boss.
Why the aluminum-manifold value is different
Holley/Weiand P/N 300-111 is an aluminum casting with supplied M6 socket-head screws, washers and an anti-seize condition. Its 16 lb-ft instruction belongs to that complete kit. The material, boss construction and friction differ from the GM composite manifold even though both attach to LS1 heads with ten fasteners.
Other aftermarket manifolds may specify oil, dry hardware, threadlocker, a different bolt length or a different final value. Use the instruction shipped for the exact revision. Brand similarity or a shared cathedral-port gasket is not permission to borrow the Weiand number.
How to read the ten-bolt diagram
Holley's figure is viewed from above with the throttle-body/front end to the left. The upper rail reads 10, 6, 2, 4, 8 from front to rear; the lower rail reads 7, 3, 1, 5, 9. Tightening begins at position 1 near the middle and alternates between rails while moving toward both ends.
Complete positions 1 through 10 at the first stage before returning to position 1. On a stock intake, repeat at 10 N-m. On the cited aluminum manifold, use the steps published with that kit. The screen diagram is a job controller, while manifold identity determines the number attached to each pass.
Port seals and false leak symptoms
Each runner must seal independently. A rolled or hardened seal can leak unmetered air into one cylinder, producing a bank-specific lean condition, idle misfire or positive fuel trim. A PCV, EVAP, brake-booster or MAP connection left open can imitate a manifold-gasket failure across several cylinders.
Before removing the intake again, smoke-test the induction system and inspect scan data by bank and cylinder. If a leak appeared immediately after installation, verify rear connections and injector O-rings as well as the ten port seals. More torque is not a diagnostic method.
Fuel and valley-area safety
- Relieve fuel pressure before opening a line and keep sparks, cigarettes and hot lamps away.
- Replace cut, flattened or fuel-swollen injector O-rings and lubricate them only with the approved product.
- Cover every intake port before cleaning the valley or gasket tracks.
- Keep debris and liquid away from knock-sensor wells and the valley-cover sealing area.
- Verify LS1 versus LS6/early versus later coolant crossover plumbing before lowering an aftermarket manifold.
- Cycle the pump and inspect the rail and every injector before cranking the engine.
LS1 intake-installation checklist
- LS1/LS6 cathedral-port application confirmed
- Stock composite or exact aftermarket part number identified
- Fuel pressure safely relieved
- Harnesses, hoses and vacuum connections labeled
- Ports covered during cleaning
- Manifold and bolt bosses inspected
- Ten correct port seals installed without damage
- Coolant crossover and valley hardware clear
- Correct bolts, washers and friction treatment selected
- Every fastener hand-starts without bottoming
- Throttle-body/front orientation verified
- One complete torque branch used without mixing values
- Fuel rail and injector O-rings leak-checked
- EVAP, PCV, MAP and brake-booster connections verified
- Idle, misfire counters and fuel trims checked after startup
Chevrolet LS1 / LS6 5.7L Gen III V8 specifications can change by model year, engine, platform, wheel, and installed component. Confirm the VIN or engine identity, part numbers, fastener condition, and the current manufacturer instructions before service.
Chevy LS1 Intake Manifold Torque Sequence Diagram FAQs
What is the stock Chevy LS1 intake-manifold torque?+
For the cited 2002 Corvette LS1/LS6 composite intake, tighten all ten in sequence to 5 N-m (44 in-lb), then repeat the sequence at 10 N-m (89 in-lb).
What is the LS1 intake bolt sequence?+
Holley's verified LS1 figure shows upper row 10-6-2-4-8 and lower row 7-3-1-5-9 with the throttle-body/front end at left. Tightening proceeds numerically 1 through 10.
Can I torque an aluminum LS1 intake to 89 in-lb?+
Not automatically. Holley/Weiand P/N 300-111 specifies 16 lb-ft with its supplied M6 screws, washers and anti-seize. Use the exact aftermarket-manifold sheet.
Is 89 in-lb the same as 89 lb-ft?+
No. 89 in-lb is about 7.4 lb-ft. Use a low-range inch-pound torque wrench for the stock composite manifold.
Do LS1 intake bolts need threadlocker or anti-seize?+
The friction condition is manifold-specific. The cited Holley/Weiand kit calls for anti-seize; do not transfer that treatment to stock or another aftermarket hardware without its instructions.
Can old LS1 intake port seals be reused?+
Replace seals that are flattened, hardened, cut, swollen or will not remain seated. New correct seals are inexpensive compared with diagnosing a lean misfire after assembly.
Does this LS1 sequence apply to an LS3 intake?+
Do not assume so. LS3/L92 rectangular-port manifolds and heads are a different application even though Chevrolet also documents light 5 and 10 N-m production-style stages on some LS3 assemblies.
What should I check after installing an LS1 intake?+
Before starting, pressure-test for fuel leaks. After startup, check vacuum and coolant connections, idle quality, misfire counters and short/long-term fuel trims on both banks.
Technical sources
TorqueSheet favors engine- and component-specific manufacturer instructions over unsourced universal values.
1Holley/Weiand LS1 aluminum intake-manifold instructionsThe component manufacturer publishes the ten-bolt physical sequence, supplied M6 hardware, anti-seize condition and 16 lb-ft final torque for manifold P/N 300-111 variants.↗2Chevrolet Performance Gen 5 Camaro LS3 power-increase kit guideChevrolet's later Gen IV guide independently documents the production-style 5 N-m and 10 N-m intake stages, while remaining a different engine application from an LS1.↗3Edelbrock Performer RPM LS1 intake-manifold application notesEdelbrock identifies the LS1/LS6-style individual port seals and its supported Gen III/IV applications, reinforcing that the manifold part number controls gasket and fastener details.↗