LS Engine Torque Specs(For All Components)

Correct torque ensures proper clamping force, prevents leaks, avoids part failure, and helps the engine operate efficiently under load.

This guide breaks down all essential LS engine torque specifications, including head bolts, main caps, rod bolts, rocker arms, intake, exhaust, flywheel, balancer, and more.

LS Engine Torque Specs

Component	Torque Spec
Main Cap Bolts (Inner)	15 ft-lbs + 80°
Main Cap Bolts (Outer)	15 ft-lbs + 53°
Side Bolts	20 ft-lbs
Rod Bolts (Factory)	15 ft-lbs + 75°
Rod Bolts (ARP)	45–50 ft-lbs (check ARP card)
Cylinder Head Bolts (Short)	22 ft-lbs + 90°
Cylinder Head Bolts (Medium)	22 ft-lbs + 90°
Cylinder Head Bolts (Long)	22 ft-lbs + 90° + 70°
Rocker Arm Bolts	22 ft-lbs
Intake Manifold Bolts	44 in-lbs → 89 in-lbs
Exhaust Manifold Bolts	18 ft-lbs
Exhaust Manifold Heat Shield Bolts	89 in-lbs
Spark Plugs	11 ft-lbs
Oil Pan Bolts (M8)	18 ft-lbs
Oil Pan Bolts (M6)	106 in-lbs
Oil Pickup Tube Bolt	18 ft-lbs
Oil Pump Bolts	18 ft-lbs
Oil Pump Cover Bolts	97 in-lbs
Balancer (Crank) Bolt	37 ft-lbs + 140°
Flywheel/Flexplate Bolts	74 ft-lbs
Camshaft Retainer Plate Bolts	18 ft-lbs
Timing Cover Bolts	18 ft-lbs
Timing Cover (Small) Bolts	106 in-lbs
Timing Chain Dampener Bolts	18 ft-lbs
Water Pump Bolts	22 ft-lbs
Thermostat Housing Bolts	18 ft-lbs
Valve Cover Bolts	89 in-lbs
Coil Bracket Bolts	89 in-lbs
Throttle Body Bolts	89 in-lbs
MAP Sensor Bolt	89 in-lbs
Fuel Rail Bolts	89 in-lbs
Injector Retainer Bolts	89 in-lbs
Knock Sensor Bolts	15 ft-lbs
Crankshaft Position Sensor Bolt	18 ft-lbs
Camshaft Position Sensor Bolt	106 in-lbs
Starter Bolts	37 ft-lbs
Bellhousing Bolts	37 ft-lbs
Torque Converter Bolts	46 ft-lbs
Engine Mount to Block Bolts	37 ft-lbs
Engine Mount Through-Bolt	74 ft-lbs
Accessory Bracket Bolts	37 ft-lbs
Alternator Bolts	37 ft-lbs
Power Steering Pump Bolts	18 ft-lbs
A/C Compressor Bolts	37 ft-lbs
Harmonic Balancer Puller/Installer Bolts	28 ft-lbs
Rear Cover Bolts (Large)	18 ft-lbs
Rear Cover Bolts (Small)	106 in-lbs
Rear Main Seal Housing Bolts	18 ft-lbs
Oil Cooler Line Fittings	18 ft-lbs
Coolant Temp Sensor	15 ft-lbs
EGR Valve Bolts (if equipped)	18 ft-lbs
PCV Valve Adapter Bolts	89 in-lbs
O2 Sensor	30 ft-lbs
Transmission-to-Engine Bolts	35–40 ft-lbs

Understanding LS Torque-to-Yield (TTY) Bolts

Many LS fasteners, especially head bolts, main bolts, and rod bolts, are torque-to-yield, meaning they stretch once torqued to spec. This provides better clamping force, but TTY bolts cannot be reused.

You must always use new:

Head bolts
Rod bolts (factory)
Main cap bolts
Crank balancer bolt

If you are repeatedly assembling an engine (racing, blueprinting), switching to ARP reusable bolts is recommended.

LS Head Bolt Torque Specs

LS heads use a three-step torque process:

1. Initial pass:

Torque all long, medium, and short bolts to 22 ft-lbs in sequence.

2. Second pass:

Turn all long and medium bolts 90°.

3. Final pass:

Long bolts: additional 70°
Medium bolts: no extra turn
Short bolts: no extra turn

This torque-angle method ensures even clamping across aluminum LS heads and composite gaskets.

LS Main Cap Torque Specs

LS main caps use a six-bolt setup for rigidity. The torque steps are:

Inner Main Bolts:

15 ft-lbs + 80°

Outer Main Bolts:

15 ft-lbs + 53°

Side Bolts:

20 ft-lbs

This gives the LS bottom end its legendary durability, especially under boost or high RPM.

LS Rod Bolt Torque Specs

Factory LS connecting rod bolts are torque-to-yield:

15 ft-lbs + 75°

If you’re using ARP bolts, use the spec on the ARP card—usually:

45–50 ft-lbs with ARP moly lube

Aftermarket rod bolts eliminate the need for torque angle and offer more consistent clamping.

LS Rocker Arm Torque Specs

All LS engines use pedestal-mount rockers. Their torque is:

22 ft-lbs

Make sure the engine is at TDC for each cylinder during installation to avoid valve spring pressure binding.

LS Intake Manifold Torque Specs

Composite LS intakes are delicate and require a two-step, low-pressure torque sequence.

44 in-lbs, then
89 in-lbs final torque

Always follow the center-out star pattern to prevent cracks or air leaks.

LS Exhaust Manifold Torque Specs

Exhaust bolts face extreme heat cycles:

18 ft-lbs

Stainless or aftermarket headers may require a re-check after the first heat cycle.

LS Crank Balancer Bolt Torque

The harmonic balancer bolt is torque-to-yield:

37 ft-lbs + 140°

An impact gun cannot achieve the final torque correctly, so always turn the angle manually. Avoid reusing the bolt.

LS Flexplate/Flywheel Bolt Torque

Regardless of the LS automatic or manual configuration:

74 ft-lbs

For boosted or high-RPM builds, many tuners upgrade to ARP hardware.

LS Oil Pump Torque Specs

Oil pump bolts:

18 ft-lbs

Ensure the pump is properly aligned over the crankshaft to avoid premature wear.

Why Accurate LS Torque Specs Matter

The LS engine platform relies heavily on aluminum components and torque-to-yield hardware. Under-torquing can cause:

Head gasket leaks
Rod bearing failure
Main bearing misalignment
Accessory and intake vacuum leaks
Flywheel loosening
Oil pump misalignment

Over-torquing is worse, it can crack aluminum blocks, distort main caps, and stretch bolts beyond safe limits.

Always use:

A calibrated torque wrench
A torque angle gauge
New TTY bolts
Proper lubrication per GM or ARP instructions

This is especially critical on LS2, LS3, LS7, and LQ4/LQ9 truck engines, where factory tolerances are tight.

FAQs

What is the torque rating of a 5.3 LS?

A standard 5.3L LS engine (such as the LM7, L59, or L33) produces 305–335 lb-ft of torque, depending on model year and configuration. The aluminum L33 variant is near the top of this range due to its higher compression ratio.

How much torque does an LS1 engine have?

The LS1 typically produces 335–350 lb-ft of torque, with slight variations based on vehicle application (Corvette, Camaro, or GTO) and tuning differences across the years.

What are the specs of an LS engine?

Most LS engines share the following specs:

V8 configuration, 90° block
Pushrod architecture with a single camshaft
Displacement range: 4.8L to 7.0L
Aluminum or iron block, depending on the model
6-bolt main bearing caps for strength
Torque output: 285–470+ lb-ft depending on engine variant
Horsepower: 270–505+ hp depending on model

The LS family is known for durability, aftermarket support, and excellent power-to-weight ratio.

Is a 5.3 a LS1 or LS2?

A 5.3L engine is neither LS1 nor LS2.

It belongs to the Gen 3 and Gen 4 LS-based truck engine family, not the performance-car LS series. The 5.3L engines (LM7, L59, L33, LC9, LY5, etc.) share architecture with LS engines but are technically Vortec/LS-based truck engines, not LS1 or LS2.

What is the difference between a 5.3 LS and a 5.7 LS?

The main differences are:

Displacement: 5.3L = 325 cu in, 5.7L = 346 cu in
Power: 5.7 LS1 engines make more horsepower and torque
Application: 5.3s are truck/SUV engines; 5.7 LS1 is a performance car engine
Compression: LS1 typically has higher compression
Block material: Many 5.3s are iron block; LS1 is aluminum
Airflow: LS1 heads flow better than most 5.3 truck heads

Overall, the 5.7 LS1 is a performance upgrade over a 5.3.

How much HP can a 5.3 LS block handle?

A stock 5.3 iron block (LM7/L59/LY5) can reliably handle 700–1,000 horsepower with proper fueling and tuning. The aluminum 5.3 blocks (L33/LS4) typically handle 550–700 horsepower safely. With forged internals and upgraded head studs, even higher levels are possible.

How much torque does a LS2 have?

The LS2 engine produces 400 lb-ft of torque, regardless of whether it’s installed in a Corvette, GTO, or Trailblazer SS. Variations may occur slightly due to exhaust and tuning, but 400 lb-ft is the standard factory rating.

Final Thoughts

LS engine torque specs are essential for a successful build. Whether you’re assembling a stock LS1 or preparing an LQ9 for boost, proper torque ensures the engine stays reliable, powerful, and leak-free. Use new torque-to-yield bolts, follow the sequences carefully, and always double-check your torque values before final assembly.

With the correct torque specs and careful attention to detail, your LS engine will deliver the performance and durability these engines are known for.