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Head Gasket Kit, L5P Duramax | 2017-2023

Merchant Automotive

$749.63 - $1,695.93
SKU:
4506
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This head gasket kit is for the L5P Duramax in 2017 to 2023 Chevy Silverado and GMC Sierra 2500HD and 3500HD trucks. It has the gaskets and seals for the parts that come off to get the heads out: valve covers, intake, exhaust manifolds, up pipes, turbo, oil and coolant lines, EGR, thermostat housing and injectors. Every part in the kit is for the L5P, so there are no extra seals for other engines.

You choose the head gaskets and head bolts when you order.

Kit Options

What's Included

Every version of the kit has these parts:

Signs of a Blown Head Gasket

  • White smoke from the tailpipe
  • Coolant loss with no leak you can find
  • Milky looking engine oil
  • Overheating
  • Bubbles in the radiator or coolant reservoir
  • Coolant pushing out of the reservoir, or a hard upper radiator hose before the engine is started
  • Coolant streaks near the head gasket

Before You Order

  • This kit fits the L5P from 2017 to 2023. For a 2024 or newer L5P, see our 2024 to 2026 L5P head gasket kit. Some parts changed for 2024, including the turbo pedestal gasket.
  • For an LB7, LLY, LBZ, LMM or LML, see our other head gasket kits.
  • Grade C is the only head gasket grade offered with this kit. If your engine needs a different grade, order the kit without head gaskets.
  • Coolant, oil and filters aren't included.

Frequently Asked Questions

Should I get the GM head bolts or head studs?
Either one works. The factory head bolts are torque to yield, so the old ones shouldn't be reused. New GM bolts are the lower cost choice. Studs clamp harder and are a common pick on tuned trucks, but they aren't required to fix a blown head gasket. If you use studs, follow the stud maker's torque steps and recheck them before the engine goes back together.

What's the difference between the ARP and PPE stud kits?
Both replace the 36 main head bolts on the L5P. Pick the brand you or your shop prefers, and follow that kit's own instructions.

Why does the bolt option have 12 extra bolts?
The L5P has 12 smaller 8mm head bolts along with the 36 main bolts. The GM bolt option includes both sets.

Will these head gaskets fit an older Duramax?
No. The L5P head gaskets only fit the L5P.

What does Grade C mean?
GM makes Duramax head gaskets in different thicknesses, called grades. The grade an engine needs depends on how far the pistons stick up out of the block. If you don't know which grade yours needs, check before ordering.

Should the heads go to a machine shop?
In most cases, yes. Have the heads checked for cracks and flatness, and check the block deck with a straightedge while it's open.

Do I need to pull the cab?
Both ways are done. Many shops pull the cab when they have a lift because it opens up the back of the engine. With the cab on, the job is tighter, especially at the firewall.

What else should I replace while the heads are off?
The water pump, thermostats, glow plugs and old coolant hoses are the parts people most often replace at the same time. See our L5P water pump kit, L5P thermostat kit and ACDelco glow plugs.

Can I order the kit without head gaskets?
Yes. Pick "none" for head gaskets and you'll get everything else in the kit.

Are the injectors included?
No. The kit has new copper seals and O-rings for all eight injectors and new fuel line washers, but not the injectors.

For warranty information, see our Warranty Policy.

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