Chevy 350 Small-Block Head Bolt Torque & Tightening Sequence
Exact head-bolt torque (65 ft-lb in 25/45/65 stages) and the full 1-17 center-out tightening sequence for the Chevy 350 small-block, plus ARP and torque-to-yield bolt notes.
Tighten a small-block Chevy cylinder head by cranking each bolt straight down one at a time and you’ll warp the head, crush the gasket unevenly, and end up chasing blown compression or coolant in your oil. The fix is simple: torque the head bolts in the correct sequence, from the centre outward, in stages. Here are the exact specs and the tightening pattern for the Chevy 350 — and the rest of the small-block family.
Chevy 350 head bolt torque specs
The right value depends on which bolts you’re running — confirm against your service manual.
| Bolt / application | Torque | Method |
|---|---|---|
| Standard bolts (cast-iron heads) | 65 ft-lb | 3 even stages (e.g. 25 → 45 → 65) |
| ARP / aftermarket bolts | 65–75 ft-lb | Multi-stage (e.g. 40–45 then 70–75); use ARP lube |
| LT-series (1995 & earlier) | 65 ft-lb | Same as standard, in stages |
| TTY bolts (1996+ LT & LS) | ~22 ft-lb + angle | Then turn (short ~67–80°, long ~80°); never reuse |
Why the tightening sequence matters
A head gasket seals combustion gas, coolant and oil at once — clamping load has to be even.
The gasket seals high-pressure combustion gas inside each cylinder and the coolant and oil passages between head and block. Fully torque one bolt before the others and you pull that corner down hard while the rest lifts — warping the deck and crushing the gasket unevenly. The payoff is blown compression between cylinders, coolant in the oil, external leaks, or a warped head that needs machining. Tightening from the centre outward, in stages, lets the gasket compress flat and uniform.
Small-block Chevy tightening pattern
17 head bolts — start at the centre and spiral outward, crisscrossing side to side at every stage.
Bolt lengths: the intake-row and inner-middle holes (1, 2, 5, 6, 9, 10, 13) take the long 3.75″ bolts; all eight exhaust-row holes (3, 4, 7, 8, 11, 12, 15, 16) take the short 1.75″; the two middle-row ends (14 & 17) take the medium 3.00″. Return each bolt to the hole it came from — the wrong length bottoms out or engages too few threads, and the torque wrench reads fine while the head is barely clamped.
Run the entire pattern at each stage (25, then 45, then 65 ft-lb) — never jump straight to final torque on a single bolt. Bolt 1 is the centre of the middle row; the spiral widens side to side and row to row until the outermost bolts (14–17) go last — never end-to-end, never one side at a time.
How to torque SBC head bolts, step by step
Clean, lubricate, then build up in three passes.
- Clean and dry the deck and bolt holes — chase the holes with a thread chaser if needed; a dirty or oiled blind hole gives a false reading.
- Lightly oil the threads and under the heads per the manual (or ARP lube for ARP bolts).
- Run the full pattern to the first stage (about 25 ft-lb), starting at the centre.
- Run it again to the second stage (about 45 ft-lb).
- Run it a final time to 65 ft-lb (or the angle spec for TTY bolts).
- Use a calibrated torque wrench — never an impact gun.
Tools and parts for the job
The right kit is the difference between a clean seal and a comeback — order anything you’re missing before you start.
Some links below are Amazon affiliate links — as an Amazon Associate we may earn a small commission at no extra cost to you.
1/2" torque wrench
The only reliable way to torque in stages to an exact value. Calibrated, 1/2" drive covers the head-bolt range.
ARP small-block Chevy head bolt / stud kit
Stronger, reusable, and consistent — with ARP’s own lube for a repeatable torque. The go-to when the factory bolts are tired or you’re building power.
Small-block Chevy head gasket set
A fresh gasket set is non-negotiable on reassembly — match it to your bore and deck for the right seal.
Common mistakes
Four ways a head job turns into a do-over.
- Skipping the pattern — tightening front-to-back or one side at a time warps the head.
- One-shot torquing — going straight to 65 ft-lb instead of building up in stages.
- Reusing torque-to-yield bolts — TTY bolts stretch permanently; always replace them.
- Dirty threads — debris or oil in a blind hole hydro-locks the bolt and ruins the reading.
Frequently asked questions
What is the head bolt torque on a Chevy 350?
For standard cast-iron heads with factory bolts, 65 ft-lb, reached in three even stages (for example 25, 45, then 65 ft-lb) following the centre-out pattern. ARP bolts typically call for 65–75 ft-lb with ARP lube — follow ARP’s instructions.
What is the head bolt torque sequence for a small-block Chevy?
Start at the centre bolts and work outward in a crisscross pattern, running the full sequence at each stage so clamping load stays even, the gasket seals and the head doesn’t warp. Follow your service manual for the exact factory numbering.
Can I reuse small-block Chevy head bolts?
Standard SBC head bolts can generally be reused if clean, straight and undamaged. Torque-to-yield (TTY) bolts on 1996+ LT and LS engines must be replaced every time — they stretch permanently when torqued.
Keep going
Bottom line: torque a small-block Chevy head to 65 ft-lb in three stages — 25, 45, then 65 — running the full centre-out crisscross pattern at every stage so the gasket compresses evenly. Clean, dry holes, the right lube, a calibrated wrench, and fresh TTY bolts where required turn a head gasket job into a one-time fix.
Video plays from YouTube when clicked. Always confirm torque values against your service manual.