GM Cylinder Head Bolts, 36 Pack, L5P Duramax | 2017-2025

GM Cylinder Head Bolts, 36 Pack, L5P Duramax | 2017-2025

This is a full set of 36 genuine GM cylinder head bolts for the 6.6L Duramax L5P. The bolts are GM 11604627, which replaces the original 11548837, and are M12 x 1.5 x 135 mm. GM lists 36 of these bolts per engine, so one pack covers both cylinder heads. Head bolts should be replaced with new ones any time the heads come off, whether for a head gasket job or head work.

Key Features

• Genuine GM 11604627, replaces 11548837
• M12 x 1.5 x 135 mm cylinder head bolts
• 36 bolts, a full set of main head bolts for one engine
• Fits 2017-2025 L5P Duramax

Benefits

Head bolts are stretched to their clamping load when torqued, and reusing them risks bolts that won't hold proper clamp load on the head gasket. A complete set of new GM bolts means every bolt torques the same, giving the new head gaskets even clamping. Commonly replaced at the same time: Head Gasket, Grade C Set of 2 | 2017 - 2024, Engine Cylinder Head Bolt (12 Pack) | 2017 - 2025.

Frequently Asked Questions

Is this enough for the whole engine?
Yes, for the main head bolts. GM lists 36 per engine. The L5P also uses smaller 8mm head bolts, sold separately in our 12 Pack.

Can I reuse my old head bolts?
No. Always install new head bolts when the cylinder heads are removed.

What about head studs?
For high-horsepower builds, the ARP Duramax Head Stud Kit | 2017 - 2023 replaces the head bolts with reusable studs.

Fitment

Fits 2017-2025 Chevrolet Silverado and GMC Sierra 2500HD and 3500HD with the 6.6L Duramax L5P. 36 required per engine. For 2001-2016 Duramax engines, use the OEM Cylinder Head Bolt 36 Pack | 2001 - 2016.

What's Included

• (36) Genuine GM 11604627 cylinder head bolts, M12 x 1.5 x 135

For warranty information or to submit a claim, see our Warranty Form.