ATK High Performance Aluminum Cylinder Heads for Small Block Chevy

Name: ATK High Performance Aluminum Cylinder Heads for Small Block Chevy
Brand: ATK ENGINES
SKU: 059-SBC64185
Price: 580.99 USD
Availability: InStock

^$580⁹⁹

Ships on Dec 02, 2026

Lowest Price Guarantee

Currently Unavailable

This product is currently not available. Please call customer service for assistance at 1-800-345-4545.

185cc Intake Runner

Small Block Chevy
Port Volume: 185cc/85cc
Valve Size: 2.020"/1.600"
64cc Combustion Chamber
Max Lift: .600"
Hydraulic Roller Springs

Assembled, Sold Individually

Material
Casting	A356-A Virgin Grade, Heat Treated to T-6
Valve Guides	Manganese Bronze
Valve Seats	Alloy, For use with Unleaded Gasoline

Valve Train
Rocker Stud Size	3/8"-24
Guide Plates	5/16" Flat
Pushrods	5/16" Hardened, *Must Check Length*
Spring Retainers	Chrome Moly Steel (7 Degree)
Valve Locks	7 Degree (HD)
Spring Locator	I.D. Locator - 1.490" x 0.060"
Valve Springs
Specifications				Pressure
Spring O.D.	Type	Max Lift	Coil Bind	Seat Load	Open Load
1.437"	Dual	0.600"	1.125"	135# @ 1.800"	340# @ 1.200"

Accessories
Spark Plugs	14mm x 3/4" Reach - Gasket Seat - 5/8" Hex
Head Bolts	JEGS 555-83400 or equivalent
Head Studs	Standard SB-Chevy
Stud Girdle	JEGS 555-20510 or equivalent
Rocker Arms	Standard SB-Chevy for 3/8"-24 Stud
Head Gasket	JEGS 555-210041 or equivalent
Accessory Bolt Locations	Stock Placement

Flow Specifications
	Intake	Exhaust
Port Volume	185cc	85cc
Valve Diameter	2.020"	1.600"
Valve Length	4.910"	4.910"
Valve Stem Seal Diameter	11/32" x .530"	11/32" x .530"
Port Dimension	2.150" x 1.300"	1.430" x 1.500" (D Port)
Flow Rate @ 0.200" Lift	130 CFM	107 CFM
Flow Rate @ 0.300" Lift	195 CFM	142 CFM
Flow Rate @ 0.400" Lift	240 CFM	172 CFM
Flow Rate @ 0.500" Lift	260 CFM	187 CFM
Flow Rate @ 0.600" Lift	265 CFM	196 CFM
Flow Rate @ 0.700" Lift	270 CFM	203 CFM
Flow Rate @ 0.800" Lift	272 CFM	207 CFM
Gasket	JEGS 555-210000 or equivalent	JEGS 555-210052 or equivalent