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SKU: C15745-071 | UPC: 191070590611
Cometic Gasket GM LSX Gen-4 Small Block V8 .071in DST Cylinder Head Gasket 4.200in Bore 1/2in & 3/8in Studs LHS for Chevrolet Performance Crate Engines
Cometic C15745-071 delivers precise sealing for GM LSX Gen-4 Small Block V8 crate engines machined to 4.200in bore. This left-hand side gasket uses .071in DST MLS construction to handle extreme cylinder pressures in racing and high-horsepower street builds. Pair with matching RHS gasket C15744-071 for complete head sealing on 1/2in and 3/8in studs.
Key Features
- 4.200in Bore Diameter: Matches LSX blocks bored or sleeved to 4.200in for zero leak alignment in stroker configurations
- .071in Thickness: Sets ideal compression height and quench for boosted or naturally aspirated LSX setups up to 15:1 ratios
- 1/2in & 3/8in Stud Compatibility: Fits ARP and factory-style LSX head studs without modification
- LHS Design: Custom contoured for left-hand side cylinder head on Gen-4 LSX blocks
- DST MLS Material: Multi-layer steel with Direct Seal Technology resists blowout under 1000+hp and nitrous applications
Product Notes
- Inspect block and head surfaces for flatness within .002in before install
- Apply light oil to studs and use moly lubricant on bolts
- Packaged flat in protective envelope to avoid bends during transit
Installation Notes
- Professional installation recommended.
- Torque in 3 stages to 70ft-lbs max using MLS-specific sequence
- Requires 1/2in ARP 2000 studs or equivalent 3/8in dowel pins
This Part Fits
| Year | Make | Model | Submodel |
|---|---|---|---|
| 2006+ | Chevrolet Performance | LSX376/480 | Gen-4 4.200in Bore |
| 2006+ | Chevrolet Performance | LSX402 | Gen-4 4.200in Bore |
| 2006+ | Chevrolet Performance | LSX454 | Gen-4 4.200in Bore |
| 2006+ | GM | LSX Bowtie Race Block | Gen-4 SB V8 4.200in Bore |
Why Choose Cometic?
- Trusted by NHRA Pro Stock and Top Fuel teams for race-proven reliability
- Laser-cut layers ensure leak-free fit on production and custom LSX castings
- Engineered in USA with stainless steel for corrosion resistance and reuse
Frequently Asked Questions
-
Q: Will C15745-071 fit LS3 or LS7 OEM engines?
A: No fits only LSX Gen-4 blocks at 4.200in bore LS3/LS7 use smaller bores like 4.065in or 4.125in -
Q: What is the material and compressed thickness?
A: Multi-layer stainless steel MLS compresses to .051in from .071in nominal for tight sealing -
Q: Does it come with a warranty?
A: Yes Cometic provides 1-year limited warranty for manufacturing defects when installed correctly
Shipping & Handling
- Method: UPS Ground / USPS Priority Mail
- Availability: In stock - ships same or next business day
- Packaging: Flat protective envelope 14in x 11in x 0.25in
- Weight: 0.35 lbs
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