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12556463 - Chevrolet Performance Parts Aluminum Cylinder Head- ZZ4 Crate Engine & '86-91' L98 Corvette - Complete

This product may require vehicle validation(s) for proper fitment. Please contact us to confirm correct vehicle fitment and usage.

Availability: This Item Has Been Discontinued


This aluminum cylinder head assembly for small-block Chevrolet V8s is ideal for street rods, fresh-water power boats, and high performance applications.GM Performance Parts' new aluminum cylinder head assembly combines the benefits of light weight, advanced design and an affordable price.

This complete assembly includes valves chrome silicon heavy-duty valve springs, retainers, 3/8" screw-in rocker studs-everything an enthusiast wants in a high-performance cylinder head package! GM Performance Parts aluminum cylinder head assemblies are based on brand new Corvette light allot casting.

The Corvette cylinder heads advanced design features include D-shaped exhaust ports that enhance the flow of burned gases, high-velocity intake runners that provide crisp throttle response, and centrally located spark plugs that improve combustion efficiency.

Valve seat inserts for 1.94" diameter intake valves and 1.50" exhaust are installed in the 58cc combustion chambers.

Raised rocker cover rails with machined sealing surfaces virtually eliminate rocker cover gasket oil leaks.This high-performance cylinder head assembly is used exclusively on High Output 5.7-liter small block V8 engines.

Unlike production Corvette cylinder heads, it is outfitted with special heavy-duty valve springs.

A pair of aluminum cylinder head offers a weight savings of approximately 50 pounds over comparable cast iron cylinder heads. This reduction in total engine weight 25 pounds each can improve handling acceleration and fuel economy.

This aluminum head assembly requires valve covers with central hold down bolts and extra-long bolts with washers.

Application List



  • 12556463
  • 12556463
  • Chevrolet Performance Parts
  • This Item Has Been Discontinued
  • New


Shipping Information

  • Item Requires Shipping
  • 24.5 lbs.
  • W8.8800” x H6.5000” x L21.0000”

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