This guide provides a full table of torque specs covering all major SBC engines, including general fasteners, cylinder head bolts, intake and exhaust bolts, connecting rods, mains, and accessory torque values.
The torque specs in this list apply to the most common generations of SBC, Gen I & Gen II, which include the 265, 283, 302, 305, 307, 327, 350, and 400-cid engines.
SBC Engine Torque Specs
| Component | Torque Spec (ft-lbs) | Notes |
|---|---|---|
| Cylinder Head Bolts (Long) | 65 ft-lbs | Torque in 3 steps; oil threads |
| Cylinder Head Bolts (Short) | 55 ft-lbs | Inside row bolts |
| Rocker Arm Studs (Screw-In) | 50 ft-lbs | Performance heads may vary |
| Rocker Arms (Nut Style) | 20 ft-lbs + adjust | Adjust lifter preload |
| Intake Manifold Bolts | 25 ft-lbs | Start from center outward |
| Exhaust Manifold Bolts | 20 ft-lbs | Retorque after heat cycles |
| Oil Pan Bolts (¼-in.) | 10 ft-lbs | Don’t overtighten |
| Oil Pan Bolts (5/16-in.) | 15 ft-lbs | |
| Valve Cover Bolts | 7–9 ft-lbs | Avoid crushing gasket |
| Water Pump Bolts | 30 ft-lbs | Long and short bolts |
| Thermostat Housing Bolts | 25 ft-lbs | Aluminum housings vary |
| Harmonic Balancer Bolt | 60 ft-lbs | Some aftermarket: 70 ft-lbs |
| Timing Cover Bolts | 6–8 ft-lbs | Aluminum covers require care |
| Timing Chain Sprocket (Upper) | 20 ft-lbs | |
| Timing Chain Sprocket (Crank) | 25 ft-lbs | |
| Flywheel / Flexplate Bolts | 60 ft-lbs | Use threadlocker |
| Clutch Pressure Plate Bolts | 35 ft-lbs | Tighten in star pattern |
| Spark Plugs (Iron Heads) | 20 ft-lbs | Carbon steel threads |
| Spark Plugs (Aluminum Heads) | 11 ft-lbs | Prevent thread stripping |
| Engine Mounts | 35 ft-lbs | |
| Bellhousing Bolts | 25–35 ft-lbs | Transmission dependent |
| Starter Bolts | 30–35 ft-lbs | Shim as needed |
| Fuel Pump Bolts | 25 ft-lbs | |
| Distributor Hold-Down Bolt | 25 ft-lbs |
Note: Performance builds or aftermarket components may have different torque values, but this guide gives you the correct baseline for stock-style builds.
Related Engine Mount Torque(For All Mount Types)
Rotating Assembly Torque Specs (SBC Engines)
| Component | Torque Spec (ft-lbs) | Notes |
|---|---|---|
| Main Cap Bolts – Inner | 70 ft-lbs | 2-bolt main blocks |
| Main Cap Bolts – Outer | 65 ft-lbs | 2-bolt main blocks |
| 4-Bolt Main – Inner | 70 ft-lbs | |
| 4-Bolt Main – Outer | 65 ft-lbs | |
| Main Cap Side Bolts (400 SBC) | 40 ft-lbs | Unique to 400 small block |
| Rod Bolts (3/8-in.) | 40 ft-lbs | Standard rods |
| Rod Bolts (11/32-in.) | 33 ft-lbs | 265/283 early rods |
| Rod Bolts (Aftermarket) | Refer to manufacturer | ARP usually 45–63 ft-lbs |
| Camshaft Sprocket Bolts | 20 ft-lbs | |
| Cam Thrust Plate Bolts | 9 ft-lbs | Common on later SBC |
| Oil Pump Bolt | 65 ft-lbs | |
| Oil Pump Pickup Tube | Press fit | Brazing recommended |
Related SBC Engine Oil Cooler Kit(Top 5 Best 2025)
SBC Engine Model-Specific Notes
While most torque specs are universal across SBC engines, a few models have unique considerations.
265 / 283 Small Block
- Many early engines used small rod bolts (11/32″), which require lower torque (33 ft-lbs).
- Early timing covers were thin stamped steel—don’t exceed the torque rating.
302 (Z/28)
- High-revving engine; builders often upgrade rod bolts.
- Main and head torque specs are the same as 327/350.
305 & 307 SBC
- Share identical torque specs with the 350.
- Thin cylinder walls—avoid over-tightening head bolts.
327 & 350 SBC
- Most common torque spec references come from these engines.
- 1969+ engines use countersunk timing tabs; same torque values.
400 SBC (Special Torque Notes)
The 400-cid small block uses:
- Longer head bolts (because of Siamese bores)
- Main cap side bolts (40 ft-lbs) are unique to the 400
- Same intake, exhaust, and accessory torque values as other SBC engines
Related Engine Oil Specification Chart(A to Z Guide)
How to Torque SBC Engine Bolts Properly
Correct torque is more than a number—it’s a method. Here are essential tips for accurate assembly:
1. Always Clean and Oil Threads
Dirty, dry threads cause inaccurate torque readings. Use engine oil or ARP lube when specified.
2. Use a Three-Step Torque Pattern
Cylinder heads, main caps, and rod bolts should be torqued in steps, such as:
- 30 ft-lbs
- 45 ft-lbs
- Final torque
This prevents distortion.
3. Follow Correct Bolt-Tightening Sequences
Especially for:
- Cylinder heads
- Intake manifolds
- Mains
- Crank sprocket assemblies
4. Use a Calibrated Torque Wrench
Inaccurate torque can damage components. Check calibration yearly.
Related Chevy Engine Swap Compatibility Chart(For All Engine Types)
Why Proper Torque Matters on an SBC Engine
Small-block Chevy engines are built with precision. Improper torque can lead to:
- Head gasket failure
- Rod bearing wear
- Main cap misalignment
- Leaking gaskets
- Cracked bolt bosses
- Vibration and oil pressure issues
Correct torque ensures the engine runs cooler, smoother, and longer.
FAQs
What is the torque spec for SBC main bolts?
Standard Small Block Chevy (SBC) main cap bolts typically torque to 65–70 ft-lbs.
- Inner bolts: 70 ft-lbs
- Outer bolts: 65 ft-lbs
- For 4-bolt main blocks, this spec stays the same. The 400 SBC also includes side bolts that torque to 40 ft-lbs. Always torque in 3 steps and follow the correct sequence to avoid distortions.
What are the torque specs for a 350 Chevy?
A Chevy 350 SBC uses these common torque specs:
- Head bolts: 65 ft-lbs (long) / 55 ft-lbs (short)
- Main cap bolts: 70 ft-lbs (inner) / 65 ft-lbs (outer)
- Rod bolts: 40 ft-lbs (standard 3/8″)
- Intake manifold: 25 ft-lbs
- Exhaust manifold: 20 ft-lbs
- Spark plugs: 20 ft-lbs (iron heads) or 11 ft-lbs (aluminum heads)
- Harmonic balancer bolt: 60 ft-lbs
- These apply to most Gen-1 350 small blocks.
What is the torque specs on a 1997 Chevy 5.7 Vortec engine?
The 1997 5.7L Vortec (L31) torque specs are slightly updated but similar to older SBC engines:
- Head bolts:
- Long bolts: 65 ft-lbs
- Short bolts: 55 ft-lbs
- Main cap bolts: 70 ft-lbs inner / 65 ft-lbs outer
- Rods: 45 ft-lbs (most Vortec rods use torque-to-yield or updated bolt styles)
- Intake manifold: 11 ft-lbs (Vortec plastic/metal hybrid intake uses LOW torque)
- Exhaust manifold: 18–20 ft-lbs
- Harmonic balancer bolt: 60–70 ft-lbs
- Timing cover: 8 ft-lbs
- Spark plugs: 11 ft-lbs
Vortec engines require special care with their intake manifold torque pattern due to their composite design.
What is the torque on the rod bolts on a 350 Chevy?
Standard Small Block Chevy 350 rod bolts torque to 40 ft-lbs when using OEM 3/8″ rod bolts.
Special cases:
- Early small rods (11/32″): 33 ft-lbs
- Aftermarket/ARP bolts: Usually 45–63 ft-lbs, depending on bolt material
- Always check bolt brand instructions—rod bolt torque varies more than most fasteners.
What is the torque spec for the crank bolt on a 350 SBC?
The harmonic balancer/crankshaft bolt on a 350 SBC torques to 60 ft-lbs.
Some performance bolts or aftermarket balancers may require 70–80 ft-lbs, but the OEM spec is 60 ft-lbs.
Using blue threadlocker is recommended to prevent loosening from engine vibration.
Final Thoughts
The SBC engine family is legendary for its durability and tunability, but proper torque specs are essential to getting the most from your build. Whether you’re assembling a stock 350 for a daily driver or a performance-built 400 for racing, following the correct specifications ensures reliability and power.
This guide covered all major SBC torque specs in a clear, table-based format so you can reference it during any rebuild or repair. Always check individual aftermarket part instructions as torque can vary, especially with ARP bolts, aluminum heads, or upgraded rods.
