How many head bolts does a big block Chevy have?
The standard factory configuration for most big-block Chevrolet engines is 16 head bolts, eight per cylinder head, across two heads.
In this article, we explain the typical count, how it is arranged, and the common variations you might encounter in restorations or performance builds.
Standard head bolt count
The typical factory setup uses eight bolts for each cylinder head on a two-headed V8, totaling 16 head bolts.
- 2 cylinder heads (left and right) with 8 bolts per head, for a total of 16 bolts.
- In many performance builds, enthusiasts replace bolts with head studs, but the total number of fasteners used to secure the heads remains tied to the head count; studs are a different hardware category and may alter torque procedures.
While 16 bolts are standard, always verify the exact block and head combination on your engine; some OEM or aftermarket blocks may have variations.
Notes for builders and enthusiasts
Bolts vs studs and torque considerations
In high-performance or race applications, builders frequently switch to head studs or studs-and-nuts for more consistent clamping and easier removal. When using studs, torque specs and thread engagement will differ from bolts and must follow the fastener manufacturer's guidelines or GM service data for the engine family.
Model- and year-specific notes
Gen I big-block Chevys such as the 396, 427, and 454 typically follow the 16-head-bolt standard. Aftermarket blocks or certain specialty engines may use alternate fastener schemes, so check the exact documentation for your block.
Summary
For most big-block Chevrolet V8s, the standard head-bolt count is 16—8 bolts per head across two heads. Variations exist in performance builds (often replaced by studs) and in certain aftermarket blocks, so always confirm the hardware with the engine’s documentation or service manual.
What are the specs on a 454 engine?
- Part Number: 19433409.
- Engine Type: Gen VI Big-Block V8.
- Displacement: 454 cu. in. ( 7.4L)
- Block: Cast iron with 4-bolt main caps.
- Balanced: External.
- Bore x Stroke: 4.250 x 4.000 in. ( 107.95mm x 101.6 mm)
- Valve Lift (in): .510 intake / .540 exhaust.
- Camshaft Duration (@ .050 in): 211° intake / 230° exhaust.
What does 4 bolt main mean on a 350?
Blocks. That's in reference to the main caps. And the number of bolts holding them to the block. There's a lot of force trying to push the crankshaft out of the bottom of the engine.
Are LS7 heads 6 bolt?
Utilizing a 6-bolt configuration, the CID LS7 castings are the ideal choice for your hotrod.
How much torque does a 632 big-block have?
876 lb-ft
With a high-lift camshaft and 12.0:1 compression ratio, the ZZ632 produces a staggering 1,004 horsepower at 6,600 rpm and 876 lb-ft of torque at 5,600 rpm—all on 93-octane pump gas.
