Dart IMCA Approved Cast Iron Small Block Chevy Cylinder Heads

IMCA Approved Stock Replacement Dart Cylinder Heads

These Dart IMCA Approved cast iron Small Block Chevy cylinder heads are approved stock replacement heads for Hobby Stock, Northern & Southern Sport Mod, and Stock Car classes (using the 500 carbuertor). We begin with a Dart 10024360 Iron Eagle S/S 165 casting. Each head is engraved and serial-numbered to conform to IMCA rules.

After extensive research and development regarding the airflow capabilities and performance characteristics of this cylinder head versus previous models, IMCA approved this Speedway Motors-exclusive IMCA Dart cylinder head and it's available for fast shipment in bare or assembled configurations.

Featuring precision cast ports and chambers, they have outstanding air flow. Assembled versions have optimized valve sizes for maximum performance within IMCA rules. 

(BARE) - Bare Cylinder Head

(HS) - IMCA Hobby Stock Heads

(SM) - IMCA Sport Mod Heads (Northern and Southern SportMod)

(SC) - IMCA Stock Car Heads 

(SCBARE) - IMCA Stock Car Bare Cylinder Heads 

Complete assembled versions include high-performance springs, 1.94"/1.50" standard length stainless steel valves, 7 degree locks and steel retainers with 3-angle valve jobs. 

• Sport Mod and Stock Car versions includes high-performance COMP Cams valve springs and handle 0.550" net valve lift, with Ferrea tool steel retainers
• Stock Car versions are .080" max flat milled w/ intake surface corrected to max out the compression rule for the IMCA Stock Car
• Hobby Stock heads feature Speedway Motors high performance valve springs 180671515

• Approved for IMCA Hobby Stock, Sport Mod and Stock Car classes (using 500 carb) as of 4/27/2020.
• Assembled heads take approximately 1-2 days for assembly and will be shipped out promptly afterward. 

• Approved for IMCA Hobby Stock, Sport Mod and Stock Car classes (using 500 carb) as of 4/27/2020.
• Assembled heads take approximately 1-2 days for assembly and will be shipped out promptly afterward. 

Material: Cast Iron

Comb Chambers: 64cc (SC) 76cc (SM/HS/BARE)

Intake Valve Dia: 1.940"

Intake Port volume: 165cc

Intake Port Dim: 1.100" W x 1.925" H

Int Port Location: Stock

Intake Gasket: Fel-Pro# 1204 or OEM type

Exh Valve Dia.: 1.500"

Exh Port volume: 65cc

Exhaust Port Dim: 1.340" W x 1.300" H

Exh Port Location: Stock location & bolt pattern

Exhaust Gasket: Fel-Pro# 1404

Flow, Intake: 210 cfm @ .500" lift / 28"

Flow, Exhaust: 138 cfm @ .500" lift / 28"

Head bolts: Stock bolts can be used

Milling: Min. 62cc = .060" (.0065" = 1cc) Flat Mill

Pistons: Most 23° aftermarket pistons.

Push Rod length: Stock (Stock length = 7.800") * Must measure *

Push Rod Guide: Stock type, integral

Retainers: Steel 1.250" = (7° )

Rocker Arm stud: Use screw-in stud w/integral nut

Spark Plug: Straight, .460" reach, tapered seat

Spring Cups: N/A, Use hardened shim or locator

Spring Pockets: Cut for 1.250" OD (.030" deeper max)

Valve Angles: 23°

Valve Length: STD = 4.890"

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

Valve Guides: Integral cast into head

Valve Guide clearance: .002" - .0025" (with .3415 dia. valve stem)

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

Valve Seals: Cut for umbrella seals

Valve Seats: Exh = Powdered Metal, .006" press

Valve Seat dim: Exh - 1.650" x 1.280" x .350"

Valve Seat angles:

• Int = 32° - 45° - 60° - 70°- 80°
• Exh = 37° - 45° - radius

Torque Specs:

• Head Bolts = 70 ft/lb (w/ oil)
• Rocker Studs = 55 ft/lb
• Manifold = 35 ft/lb

Block Use: Any SBC, Iron or Aluminum

Weight: 52 lbs Bare – 58 lbs Assembled