This highly evolved, race-proven cylinder head is capable of supporting in excess of 800 horsepower in “as cast” form. World’s MERLIN III aluminum heads are available with 310cc or 350cc intake runners. The exhaust ports are 132cc.

For those seeking more power, World now offers MERLIN III heads with CNC-ported combustion chambers and ports. This raises the bar to a choice of 345 or 380cc intake runners. The port designs were developed by noted NMCA, NHRA, NMRA horsepower merchant, Kuntz & Co. and have proven their effectiveness on the track.

We’ve taken our popular MERLIN III design and CNC-ported the combustion chambers and ports. The net result is a head that combines excellent flow and velocity and has been proven to produce 40 horsepower more than the as-cast MERLIN on a 572 C.I.D. engine. It’s also a great value!

Casting ID Number: WOR-070B, WOR-070C
Material: 355-T6 alloy high density aluminum
Valve Seats: Intake (hardened), exhaust (hardened)
Valve Guides: Manganese bronze
Spring Seats: Machined for 1.560" (can be machined for 1.625")
Valves: Manley stainless steel valves in assemblies
Valve Diameter: 2.300" intake, 1.880" exhaust (11/32" stem)
Guide Plates: Stock (for best fit use World #830466-8)
Rocker Arm Studs: Screw-in style
Rocker Arms: Standard
Intake Runner: 310cc or 350cc, standard port location
Exhaust Ports: 132cc, standard location
Combustion Chamber: 119cc
Spark Plug: 14mm .750" reach gasket style
Valve Job: Multi-angle intake and radiused exhaust
Valve Cover Rail: Raised
Valve Angle: Stock 24°
Accessory Bolt Holes: Stock
Chamber Design: Open

Spring Specs
1.550": 150 lbs. @ 1.910", 350 lbs. @ 1.260", coil bind @ 1.210", max lift @ .650"
1.550": 225 lbs. @ 1.910", 520 lbs. @ 1.210", coil bind @ 1.160", max lift @ .700"
1.640": 275 lbs. @ 2.000", 600 lbs. @ 1.200", coil bind @ 1.050", max lift @ .900"

Head Flow
310cc @ .700 Lift
372 intake, 268 exhaust (Super Flow 1050)
400 intake, 290 exhuast (Super Flow 600)
350cc @ .800 Lift
382 intake, 280 exhaust (Super Flow 1050)
410 intake, 303 exhuast (Super Flow 600)
CNC Ported 350cc @ .800 Lift
405 intake, 297 exhaust (Super Flow 1050)
434 intake, 321 exhaust (Super Flow 600)
CNC Ported 375cc @ .800 Lift
410 intake, 300 exhaust (Super Flow 1050)
440 intake, 324 exhaust (Super Flow 600)
All heads flowed with a standard .750" intake plate, without exhaust tube, and 28" of water.