Order Status & Returns
Gift Cards
Help Center
1-800-345-4545
Vehicle Info NeededENGINETECHPART NUMBER: 416-HC403L-OS
HC403L-OS MLS Head Gasket for 2001-2016 Chevrolet, GMC, Hummer 6.6L
$18399
Ships on Sep 14, 2026
Lowest Price GuaranteeGM
Head Gasket2001-2016 Chevrolet, GMC, Hummer 6.6L Multi-Layer Steel (MLS) Construction Sold Individually
The Enginetech HC403L-OS is a replacement MLS head gasket for HEAD GSKT (1) LH 6.6L DURAMAX O/S BORE MLS .0413" THICK engines, providing an OE-quality combustion chamber seal.
Enginetech HC403L-OS Head Gasket Features:
- Fitment: HEAD GSKT (1) LH 6.6L DURAMAX O/S BORE MLS .0413" THICK
- Multi-Layer Steel (MLS) head gasket construction
- Diesel engine application
- Engineered to OE specifications for direct replacement
- Note: Left. MLS.0413 thickness. 4.173 O/S fire ring ID. Increased ID for bored blocks. Use new head bolts. MLS Grade C .0413 thickness. Oversize bore.
Part TypeHead Gasket
BrandENGINETECH
Package Height0.5
Package Width9.0
Package Length16.5
Weight1.0 PG
Part CategoryReplacement Parts
QuantitySold individually
FitmentHEAD GSKT (1) LH 6.6L DURAMAX O/S BORE MLS .0413" THICK
MaterialMulti-layer steel (MLS)
Part FitmentDirect Fit
Vendor Part NumberHC403L-OS
Package Qty1
Package TypeEA
No Questions
No Reviews
Items You Need
![Engine Assembly Lube [4 oz. Bottle]](https://www.jegs.com/images/mini_200/500/555/555-28000.jpg)
![1-Ton Automotive Shop Crane [Boom Operating Range: 34 in. to 45 in.]](https://www.jegs.com/images/mini_200/500/555/555-81044k.jpg)
JEGS
1-Ton Automotive Shop Crane [Boom Operating Range: 34 in. to 45 in.]
Part Number : 555-81044K
$23698
![Rotating Engine Stand [1000 lb. Capacity]](https://www.jegs.com/images/mini_200/500/555/555-80059.jpg)
![Round Magnetic Parts Tray [5 1/2 in. Round]](https://www.jegs.com/images/mini_200/500/555/555-80080.jpg)
![Socket Set, 3/8 in. & 1/4 in. Drive [SAE/Metric 52-Piece]](https://www.jegs.com/images/mini_200/500/555/555-81565.jpg)
JEGS
Socket Set, 3/8 in. & 1/4 in. Drive [SAE/Metric 52-Piece]
Part Number : 555-81565
$2199$33.99
You Save$12.00
![Plier Set [5-Piece]](https://www.jegs.com/images/mini_200/500/555/555-w1717.jpg)
![Break-In Oil, 10W30 [1 Quart, 32 oz.]](https://www.jegs.com/images/mini_200/500/555/555-28067.jpg)
![Fender Cover with Pocket [23 in. W x 31 1/2 in. L]](https://www.jegs.com/images/mini_200/500/555/555-65010.jpg)
JEGS
Fender Cover with Pocket [23 in. W x 31 1/2 in. L]
Part Number : 555-65010
$1499$16.99
You Save$2.00
![Penetrating Oil [11 oz. Aerosol Can]](https://www.jegs.com/images/mini_200/600/639/639-11043.jpg)
![Brake Parts Cleaner [14 oz. Aerosol Can]](https://www.jegs.com/images/mini_200/500/555/555-72311.jpg)
JEGS
Engine Storage Bag 48 in. L x 35 in. W x 34 in. H
Part Number : 555-80039
$1199$12.99
You Save$1.00
![Mechanic Chair & Step Stool on Wheels [300 lb. Capacity]](https://www.jegs.com/images/mini_200/500/555/555-81156.jpg)
JEGS
Mechanic Chair & Step Stool on Wheels [300 lb. Capacity]
Part Number : 555-81156
$9099$111.99
You Save$21.00
![Heavy-Duty Steel Workbench [59.5 in. x 27.5 in. Bench Top]](https://www.jegs.com/images/mini_200/500/555/555-81440.jpg)
JEGS
Part Number : 555-81044K
$23698
Some parts are not legal for use in California or other states with similar laws / regulations
