Dart PRO1 Small Block Chevrolet Platinum 180cc/64cc 23° Aluminium Cylinder Head Assembled suit hydraulic roller or solid flat tappet cam. .620" max lift
Excellent street, strip, oval track, truck or marine performance upgrade. Maximum torque and throttle response from idle to 6,000 RPM. Best for 327-400 cubic inch engines. Works with most standard components.
Dart’s PRO1 23° 180cc Platinum series heads utilize wet flow technology. Independent tests have demonstrated an average 25 horsepower gain over the original trend setting PRO1 design.
These 180cc as cast heads out perform many larger heads in a wide range of applications. Long wearing Bronze valve guides, screw-in studs, multi-angle intake seats and hardened, radiused exhaust seats are standard.
Assemblies include Stainless Steel valves, premium springs, locks, retainers, studs, guide plates and seals.
Cylinder Head is sold individually (2 required per engine)
Part# 11111112P
Material: RMR Cast Aluminium Alloy
Comb Chambers: 64cc
Intake Valve Dia: 2.02”
Intake Port volume: 180cc
Intake Port Dim: 1.180w x 2.095h
Int Port Location: Stock
Intake Gasket: Fel-Pro # 1205
Exh Valve Dia.: 1.600”
Exh Port volume: 75cc
Exhaust Port Dim: 1.375” x 1.325” w
Exh Port Location: Stock location & bolt pattern
Exhaust Gasket: Fel-Pro# 1404 or 1405
Flow, Intake: 257 cfm @ .500” lift / 28”
Flow, Exhaust: 172 cfm @ .500” lift / 28”
Head Bolts: Dart bolt kit PN# 66220011
Head Studs: Dart stud kit PN# 66120011
Manifold: Dart dual plane 42811000
Milling: Min. 58cc = .060” (.0065” = 1cc) Flat Mill
Angle mill .125” safely / .200” = 49cc 1.5° (carefully)
Pistons: Most 23°aftermarket pistons.
Push Rod length: Stock thru +.100” Should always measure (Stock length = 7.800”)
Push rod Guide Plate: Dart adjustable guide Plate PN# 27001410
Retainers: Steel (10°) / 1.250” (7°)
Spark Plug: Angle, .750” reach, gasketed seat
Spring Pockets: 1.550” OD (.030” deeper max)
Springs: Our Assembly: 1.437D = 130# @ 1.800” / .600” max
Valve Length: Std. = 4.915” 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” stud mount
Valve Guides: .439” OD Int = Mag-bronze Exh = Mag-bronze (.002” press) .530 seal
Valve Guide length: 2.100”
Valve Guide clearance: .0014” - .002” (with our .3415 dia. valve stem)
Valve Guide Spacing: 1.890” moved .030” from stock
Valve Seats: Powdered Metal, .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°- 80° Exh = 37° - 45° - radius
Stud Girdle: Dart stud girdle PN# 64110002
Torque: Head Bolts = 70 ft/lb
Rocker Studs = 55 ft/lb
Manifold = 35 ft/lb
Block Use: Any SBC Iron or Aluminum
Weight: 28 lbs Assembled
* Photo for illustration purposes only
23 degree cylinder heads