Dtomi Copper Header Collector Gasket 2PCS — Oval-Port SBC Fit for 305/327/350/383, Heat-Resistant Seal

Dtomi 2PCS copper header collector gaskets are oval-port exhaust seals designed to replace PH306 and reliably seal Small Block Chevy (SBC) header-to-head connections.

This pair of copper SBC header gaskets is manufactured to restore a tight, heat-resistant seal between the cylinder head and exhaust header on 327, 305, 350 and 383 small block Chevy engines. Made from copper for thermal resilience and improved malleability, these gaskets are precision-cut to fit oval ports without trimming. They arrive ready to install and are backed by one year of quality support, making them a practical replacement during header installation or exhaust leak repair.

How do these gaskets stop exhaust leaks?

The copper material and precisely stamped oval profile conform to the flange faces to block exhaust gas escape at the header-to-head joint. Copper's softness allows it to cold-seal under bolt torque while resisting long-term heat fatigue compared with many composites.

• Precise oval-port cut matches SBC header openings for a consistent seal.
• Copper composition conforms under torque to fill flange imperfections.
• Reinforced construction reduces blowout and shrinkage over time.

Will these fit my Small Block Chevy engine?

These gaskets are intended for small block Chevy engines with oval header ports—commonly used on 327, 305, 350, and 383 variants. They are sold as direct replacement pieces for part number PH306, but always verify port shape and bolt pattern before purchase to ensure compatibility.

• Designed for SBC oval port headers on 327/305/350/383 engines.
• Replaces PH306—confirm this number against your existing gasket.
• Precision-cut to avoid trimming or modification during installation.

What are the installation and durability benefits?

Installation is straightforward: the gaskets are sized for a direct fit on compatible headers and require no special preparation. Copper's combination of softness and heat tolerance provides a reliable seal while resisting common failure modes like thermal shrinkage and blowout.

• Push-fit, bolt-down installation with no trimming required.
• Copper resists heat cycling and maintains a tight seal under torque.
• Sold as a pair—enough gasket material for both sides of many header installs.

What should I check before buying?

Confirm your header port type (oval), engine application (Small Block Chevy), and whether your current gasket or parts list references PH306. Also verify flange condition—clean, flat mating surfaces improve sealing performance and extend gasket life.

• Verify oval-port headers and small block Chevy application.
• Compare existing part number to PH306 for a direct match.
• Prepare clean, flat flange surfaces before installation for best results.

Who is this for: These Dtomi copper header collector gaskets suit vehicle owners, restoration hobbyists, and independent mechanics working on classic or performance Small Block Chevy engines who need a robust, easy-to-install exhaust seal. They’re particularly appropriate if you want a straightforward PH306 replacement built to handle repeated heat cycles while maintaining a tight header-to-head connection.