All cylinder heads are priced each!

GM Performance Parts is pleased to offer our Bowtie line
of high performance street heads. They come with rectangular
or oval intake port configuration, thick deck surfaces, and high
velocity airflow passages. These heads also offer increased
machining tolerances to live up to your high performance needs.
With good throttle response and mid-range torque, the Bowtie
line of big-block heads are perfect for street/strip big-block fans
who want good low end grunt and loads of top end power.

• • 356-T6 Aluminum
• • 9/16" thick decks
• • No heat risers
• • Will work on Mark IV and Gen V and VI cylinder blocks
• • 1.55" Valve spring seat diameter
• • Heli-coiled 7/16" screw-in rocker stud holes
• • Designed for use with 3/8" pushrods
• • Available as oval and rectangle ports
• • As-cast intake and exhaust ports
• • Use intake gasket P/N 12366985 and bolt kit P/N 12367959
• • Use head gasket P/N 12363414 for bores to 4.370" and
• P/N 12363413 for bores 4.470" to 4.540" (Mark IV)
• • Use head gasket P/N 12363412 for bores to 4.370" and
• P/N 12363411 for bores 4.470" to 4.540" (Gen V & VI)
• • Use Head bolt kit P/N 12367779

This head is assembled with the following components:
12366987 2.25" Intake Valves
12366990 Valve Spring Retainers
88963128 Exhaust Valves
12366992 Valve Locks
88963934 Valve Springs
88963936 Valve Seals
88963937 Valve Spring Shims
3921912 Rocker Arm Studs
88963935 Valve Spring Locators
3860038 Pushrod Guideplates