Big Block Chevy Merlin III Cast Iron Cylinder Head 320cc Rectangular Intake Ports

Name: Big Block Chevy Merlin III Cast Iron Cylinder Head 320cc Rectangular Intake Ports
Brand: WORLD PRODUCTS
SKU: 955-030620-3
Price: 1641.14 USD
Availability: InStock

^$1,641¹⁴

Ships on 09/14/2026

Lowest Price Guarantee

Big Block Chevy Merlin III Cast Iron Rectangular-Port Cylinder Heads

320cc Rectangular Intake Ports
119cc Combustion Chambers
2.300'' Int/1.880'' Exh Valves
1.550'' Valve Springs, .700'' Max Lift for Solid Roller Cam
Assembled, Sold Individually

Valve Spring Specs: 1.550' Dual Valve Springs 225# Seat, .700' Max Lift

Emissions Note:

This part is only legal for sale and use on Uncontrolled (Non-Emissions Controlled) Vehicles or on vehicles used solely for the purposes of closed competition racing.

CLICK THIS LINK FOR IMPORTANT CARB & EPA EMISSIONS INFORMATION ABOUT THIS PART

Improved Performance Over Chevy's Legendary LS6 Heads!

Merlin 269cc Oval Port heads are excellent for most street-driven big-blocks up to 468ci. They'll out-perform larger heads in many applications. When larger engines (454 to 540ci) require added flow, choose the Merlin Rectangle Port cylinder heads. With RightCast 320cc and 345cc intake runners, you can expect solid gains in air/fuel mixture combustion charges. These World Products heads will really respond to higher compression ratios, and are ideally suited for hot street/strip cars.

Technical Specifications

Material: High density cast iron
Valve Seats: Integral intake,hardened steel exhaust
Valve Guides: Integral cast iron
Valve Spring Seats: Bare castings machined for 1.550'' springs
Valve Size: 2.300'' x 1.880''
Exhaust Flange: Port location raised .250'' , accessory bolt holes, requires ARP Head Bolts #070-135-3605.
Included In Base Assembly: Erson stainless steel valves, ring and band style (-1 and -2 models) or PC style (-3 and -4 models) valve seals, 1.550'' (-1, -2 and -3 models) or 1.640'' (-4 models) valve springs, Erson 7° (-1 and -2 models) or 10° (-3 models) retainers and keepers.

Recommended Installation Accessories
Head Gaskets: Fel-Pro 375-1017-1 or equivalent
Pushrods: Requires heat treated pushrods
Rocker Arm Studs: 7/16'' with 7/16''-14 base thread
Pushrod Guideplates: BBC Stepped 3/8''
Spark Plugs: Accepts 14mm .460'' reach tapered seat 5/8'' hex (AC Delco R42TS/R43TS) or equivalent. Heat range may vary. Consult with engine builder.
Intake Gasket: Fel-Pro 375-1212 or equivalent for oval port head. Fel-Pro 375-1211 or equivalent for rectangle port head.
Exhaust Gasket: Fel-Pro 375-1410 or equivalent
Head Bolts: 8 longer than stock required (955-832015-8)