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Cometic C5712-120 MLS Cylinder Head Gasket Pontiac Bore - 400/428/455 V8 4.300

(Pontiac GTO 1968-73, Firebird 1968-79, Grand Prix 1968-77, Grand Am 1973-75, Bonneville 1968-78, LeMans 1968-77, Catalina 1968-78 + 12 more models)

Manufacturer

Picture for manufacturer Cometic

Part Number

C5712-120
8 reviews
Sale Price

$232.11

Estimated ship date Friday, November 27

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Product Details

The Cometic C5712-120 is a premium Multi-Layer Steel (MLS) cylinder head gasket engineered specifically for Pontiac 400, 428, and 455 cubic inch V8 engines. This high-performance gasket features a compressed thickness of .120 inches and a 4.300-inch bore diameter, making it ideal for both stock rebuilds and performance applications.

Key Features:

  • Multi-Layer Steel (MLS) construction provides superior sealing and durability
  • .120" (120 thousandths) compressed gasket thickness
  • 4.300" bore diameter optimized for Pontiac big block engines
  • Handles high cylinder pressures in performance and racing applications
  • Embossed stainless steel layers with elastomeric coating for maximum conformability
  • Resists blowout and maintains seal integrity under extreme temperatures
  • Reusable in most applications when properly installed

Cometic MLS gaskets are the preferred choice for engine builders and performance enthusiasts who demand reliable sealing in high-compression and forced induction engines. The multi-layer design allows the gasket to adapt to minor surface imperfections while maintaining consistent clamping pressure across the entire sealing surface.

Products specifications

Fits

Pontiac GTO 1968-73, Firebird 1968-79, Grand Prix 1968-77, Grand Am 1973-75, Bonneville 1968-78, LeMans 1968-77, Catalina 1968-78, Tempest 1968-70, Parisienne 1968-74, 1976, Grandville 1971-75, Executive 1968-70, Grand LeMans 1975-77 + 7 more models

Prop 65

WARNING: Cancer and Reproductive Harm - www.p65warnings.ca.gov

Material

Multi-layer Steel

Found this store thru a google search. Had good reviews so I went for it. Liked that they have google checkout. Email notification was great, tracking number was there. Last but not least they had the best price for my Airaid intake tube.

Great price for percys

We ordered a Thule 9003 Raceway 2-bike rack for my 2011 Honda Civic and it arrived in 2 days. We were very surprised at the fast service. I also had my thoughts that it wouldn't be the exact name brand product I was looking for and a off brand but the same type and I have to say it was exactly the product I wanted. The price was great too. I researched several dealers and Autoplicity was the lowest price at $100 less than others and that included the shipping. I would definitely order from Autoplicity again.

Excellent service, incredibly fast shipping and delivery. Would DEFINITELY do business with again.

quick & easy

Recently placed an order for some head studs for my car. They were much less expensive at autoplicity than elsewhere. I was surprised I hadn't heard anything back after a couple days, but was reassured that orders are processed within 24 business hours (3 days), not 24 hours (which I misread in my confirmation email). Just received a shipping confirmation with a tracking number today.

I have had a very good experience with Autoplicity and will look for more parts here. I called Customer Service and they were very good and accurate with me. It was easy, they were very nice, immediate response, and great price.

They made a mistake with the shipping address, but, they took care of it very politely and professionally. Very nice. Thanks.

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