Product Description
Cummins 5271251 — Cylinder Head Gasket (+.020 Thickness) for ISB/QSB 6.7L
MPN: 5271251 | Also Known As: +.020 service head gasket, oversize thickness head gasket | Use Case: Select when machining requires +.020" thickness (verify by piston protrusion/ESN)
Why This Part
- ✓ OE sealing performance for ISB/QSB 6.7 platforms.
- ✓ +.020" service thickness to maintain proper compression after decking/machining.
- ✓ Direct-fit for Ram 6.7L 2007.5–2018 when +.020" is specified (verify by VIN/ESN).
- ✓ Built to Cummins specifications for durability under load and heat.
Quick Specs
| Type | Cylinder head gasket, service thickness |
|---|---|
| OE Part # | 5271251 (+.020" thicker than standard) |
| Engine Family | ISB 6.7L / QSB 6.7L |
| Qty Required | 1 per engine (sold individually) |
Verified Fitment (Automotive)
| Year Range | Engine | Chassis |
|---|---|---|
| 2007.5–2018* | Ram 6.7L ISB (24V Common-Rail) | Ram 2500/3500 |
*Thickness note: 5271251 is the +.020" service gasket—use only when machining or piston protrusion specs call for this thickness. Always confirm by VIN/ESN and measurement.
Industrial/Off-Highway: Used primarily on QSB/ISB 6.7 applications (Tier-rated variants). Verify by ESN.
Often Paired With
- Head fasteners: new OE head bolts or ARP head studs (as required)
- Upper engine gasket set and injector sealing components
- Fresh coolant & oil/filter after reassembly
What’s In The Box
- (1) Genuine Cummins Cylinder Head Gasket 5271251 (+.020")
Install Tips
- Measure piston protrusion and follow Cummins spec to select correct gasket thickness.
- Check surface finish/flatness after machining; clean deck and head thoroughly.
- Follow torque/angle procedures; retorque only if the service manual calls for it.
FAQ
WILL THIS FIT MY 6.7L CUMMINS RAM?Yes—when a +.020" service gasket is required, this part applies to most 2007.5–2018 Ram 6.7L ISB applications. Always verify by VIN/ESN and thickness measurement.
WHAT DOES “+.020” MEAN, AND WHEN SHOULD I USE IT?It’s thicker than the standard gasket by 0.020". Choose it after head/block machining or when piston protrusion measurements indicate a thicker gasket is necessary.
IS THIS A GENUINE CUMMINS GASKET?Yes—OE Cummins 5271251 built to factory specifications for sealing and durability.
DO I NEED NEW HEAD BOLTS OR STUDS?Best practice is to use new head bolts or upgrade to studs as required by your build and service manual.
DOES THIS REPLACE THE STANDARD-THICKNESS GASKET?No—this is the +.020" service thickness. Use the standard thickness when no machining or measurement calls for a thicker gasket.
Product Videos
Custom Field
Product Reviews
1 Review Hide Reviews Show Reviews
-
Dodge 6.7 Head gasket
The head gasket fit as it should but have not run it yet. Will try to remember to update my review after I put a few 1000 miles on it.
