Aluminum Dart 335 360 Heads Complete Fully Assembled Big Block Chevy on 2040-parts.com

Dart Pro1 355 CNC Aluminum Heads for Big Block

These are brand new "repaired defective" cylinder heads. Both of these heads had a small 3mm section of porosity in the end chambers. The defects were repaired with weld and blended back in. The price you see is for a pair of bare heads. One of these heads has a very light gold marine coating and the other does not, its barely noticable.

• Premium alloy: Dart aluminum heads are cast from virgin 355-T61 aerospace alloy for superior strength and integrity.
• Bolt on compatibility: 2 degree rolled valve angle and standard spacing accommodates all stock accessories.
• Heart shaped 121cc chambers improve combustion efficiency.
• CNC machining ensures that every chamber has the same volume so that every cylinder maintains equal compression.
• Raised spark plug location improves flame travel for a quicker, more complete burn, producing more power.
• Multi-angle intake seats and radiused exhaust seats greatly improve air flow.
• Hardened exhaust seats are compatible with unleaded gasoline.
• Exhaust ports raised .300" to improve flow (requires 1" longer head bolts next to exhaust ports).
• Spark plug holes are machined for gasketed 3/4" reach plugs.
• Manganese bronze valve guides ensure long term reliability.

Part# 19474030
Material: 355-T61 alum alloy
Comb Chambers: 121cc
Intake Valve Dia: 2.300”
Intake Port Dim: 1.760”w x 2.500”h
Int Port Location: Stock
Intake Gasket: Mr. Gasket# 121
Exh Valve Dia.: 1.880”
Exh Port volume: 138cc
Exhaust Port Dim: 2.000”w x 1.740” h
Exh Port Location: Raised .300” STD bolt pattern
Exhaust Gasket: Fel-Pro 1412
Exhaust Head Bolts: 1” longer than stock (4) ea.
Flow, Intake: (355) 415 cfm @.800 lift/28”
Flow, Exhaust: 303 cfm @.800 lift/28”
Head Bolts/studs: Bolts – ARP# 135-3603 Studs – ARP# 235-4103
Manifold: Rect. Port Dart (opening - 1.575”x 2.250”) 6.25” tall
Milling: Min. 110cc. (.005” = 1cc) Flat mill only.
Pistons: Most aftermarket pistons.
Push Rod length: Avg. +.200” / +.250” Should always measure Stock length Int. = 8.275” / Exh = 9.250”
Push Rod Guide Plate Must use Dart PN# 27001230-4
Retainers: 1.625” - Tit / 1.550” - Moly Steel (10)
Spark Plug: .750” reach, gasketed. Autolite AR3933 Street AR3924
Spring Cups: 1.625” - .035 cup / 1.550” - ID locator
Spring Pockets 1.740” OD for 1.625” cup (.030” deeper max)
Springs: Our Assembly: 1.625D = 275# @ 2.000” / .850” max P.S.I
Valve Angles: Int - 24, Exh - 15 (Rolled 2) 4 cant
Valve Length: Int - 5.505” (+.250) Exh - 5.435” (stock)
Valve Stem Dia: .3415” - 11/32”
Valve Train: STD BBC 7/16” stud mount
Valve Guides: 1/2” OD Mag - bronze Cut for .530” PC seals (.002” press)
Valve Guide length: Int - 2.250” Exh - 2.250”
Valve Guide clearance: .0014” - .0021” (with our .3415 dia. valve stem)
Valve Guide Spacing: Exh moved .045” away from Int
Valve Seats: Powdered Metal, .006” press (TIR .004)
Valve Seat dim. Int. - 2.450” x 2.000” x .375” Exh - 2.000” x 1.600” x .375”
Valve Seat angles: Int = 32 - 45 - 60 - 70 - 80° Exh = 37 - 45 - radius
Stud Girdle: Must use DART design. Part# 64110001
Valve Covers: Part# 68000040 Inverted flange
Torque: Head Bolts = 70 ft/lb Dart inner head studs 3/8-7/16 = 50 ft/lb
Rocker Studs = 55 ft/lb
Manifold = 35 ft/lb
Block Use: Mark IV, Gen V, and Gen VI with proper head gasket
Weight: 29 lbs each