DART Pro 1 180cc 23 degree Aluminum Head

PRO 1 aluminum cylinder heads for small-block V8’s deliver advanced airflow technology at an unbeatable price! There’s a PRO 1 head for virtually every small-block engine. We offer a choice of four intake runner sizes (180cc, 200cc, 215cc, and 230cc), two chamber volumes (64cc and 72cc), five valve diameters, and straight or angled spark plugs. We’ve improved the original small-block design with extra-thick decks and high-capacity water jackets that increase reliability in high-performance applications. Hardened exhaust seats and long-lasting mag-bronze valve guides significantly extend cylinder head life. PRO 1 heads are engineered for easy installation.
They use standard small-block pistons, headers, and valvetrain components, and are bolt-on replacements for most conventional 23° heads.

Pistons: Most 23°aftermarket pistons.

Push Rod length: Stock thru +.100" Should always measure (Stock length = 7.800")

Push rod Guide Plate: Must use Comp Cam # 4808 (flat)

Retainers: Steel (10°) / 1.250" ( 7°)

Spark Plug: Angle or straight, .750" reach, gasketed, Autolite AR3933

Spring Pockets: 1.550" OD (.030" deeper max)

Springs:

1.250S = 110# @ 1.700" / .520" max Comp 981

1.437D = 130# @ 1.800" / .620" max Comp 987

1.550D = 195# @ 1.900" / .690" max Comp 954

Valve Length: Std 4.890" w/ 1.250 & 1.437 / 5.015" (+.100) w/ 1.550

Valve Stem Dia: .3415" - 11/32"

Valve Train: Std SBC 3/8" or 7/16" Rocker Studs

Valve Guides: 1/2" OD Int = Mag-bronze Exh = Phos-bronze (.002" press)

Valve Guide length: 1.950"

Valve Guide clearance: .0014" - .002" (with our .3415 dia. valve stem)

Valve Guide Spacing: 1.890" moved .030" from stock

Valve Seats: Hardened Ductile Iron, .006 Press

Valve Seat dim. Int - 2.160"x 1.810" x .350", Exh - 1.650"x 1.350"x .350"

Valve Seat angles: Int = 32° - 45° - 60° - 70° Exh = 37° - 45° - radius

Stud Girdle: Use any standard SBC stud girdle

Torque Specifications:

Rocker Studs = 45 ft/lb

Manifold = 35 ft/lb

Block Use:

Weight: