World Products 043650-1 – Cylinder Head Cast Iron Chevy Small Block S/R 170cc 67cc 23Degree 1.940″ x 1.500″ Straight Plug 87 and up. Assembly w/ 1.250″ springs for hydraulic flat tappet lifters646.81

World Products 043650-1 – Cylinder Head Cast Iron Chevy Small Block S/R 170cc 67cc 23Degree 1.940″ x 1.500″ Straight Plug 87 and up. Assembly w/ 1.250″ Springs for Hydrailic Flat Tappet Lifters

World’s S/R cylinder Head are the preferred alternative to expensive OEM castings or junkyard rebuilds. These Head are designed with extra-thick decks and walls for improved reliability as well as equipped with hardened steel exhaust seats that are compatible with today’s unleaded gasolines. Needless to say, the S/R is substantially more durable than OEM castings.Valve cover rails have been raised and carefully machined to eliminate oil leaks and the Head can accommodate either early style perimeter or late model center bolt valve covers.S/R Cylinder Head  are fully 50-state emissions legal and because they are an OEM replacement head, they are legal for use by many oval tracks and race Sanctioning organizations…

NHRA  World castings #043600 and #043610 as   replacements for Chevrolet 041, 186, 291, 462 and 492 cylinder Head.

United Rebel Sprint Series World Products S/R  Cylinder Head are the ONLY Head allowed.

WISSOTA Approved for use by The Amsoil Dirt Track Series.

GM REPLACEMENT PART NUMBER CONVERSIONS

World #043600 = GM 333882, 460703, 462624, 468642, 3911032,3927187,   3932141, 3946813, 3947041, 3970126, 3973414, 3973493* 3974387, 3981598*,   3986339, 3998920, 3998991, 3998993, 3998997, 14020516, 14020517, 14020556,   14071114, 14079261

World #043610 = GM 3795896, 3814482, 3827185, 3884520, 3890462,   3911032, 3917290, 3917291, 3927186, 3932441, 3946813, 3973370, 3998993

TECHNICAL SPECS

• Casting ID Number: I-052, I-058
• Material: High density cast iron
• Valve Seats: Intake (integral), exhaust (hardened)
• Valve Guides: Integral cast iron
• Spring Seats: Machined for 1.560″
• Valves: ERSON stainless steel valves in assemblies
• Valve Diameter: 2.020″ intake, 1.600″ exhaust   (11/32″ stem)
• Rocker Arms: 1.5 ratio (1.6 ratio may require elongation of pushrod holes)
• Intake Runner: 170cc, standard port location
• Exhaust Ports: 65cc
• Combustion Chamber: 67cc or 76cc
• Spark Plug: 14mm 5/8″.460″ reach tapered style. EX. ACCEL 276 or 276S
• Valve Job: Multi-angle intake and radius exhaust
• Valve Cover Rail: Raised w/ perimeter
• Valve Angle: Stock 23°
• Accessory Bolt Holes: Stock
• Guide Plates: Not machined for them
• Rocker Arm Studs: Not Included
• Springs: 1.250″, Max Lift .560″

World Products S/R 170cc Iron Head Flow Data 
Valve Lift–.300 –.400 –.500 –.600 –.700 –.800 

1.940 —-   182 — 216 — 232 — 225  –217 — 217
1.500 —-   125 — 147 — 161 — 168 — 169 — 169   

Methods used: Superflow 600, Flowed at 28″ with a bowl blend 1″ down, 1″ radiused entry plate on the intake port, No exhaust tube, Using Manley Race Master valves.

Heads are sold individually.