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.

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''
Rocker Arm Studs: 7/16'' screw-in style with hex shoulder furnished with assembly
Exhaust Flange: Port location raised .250'' , accessory bolt holes, requires ARP Head Bolts #070-135-3605.

Included In Base Assembly: Manley RaceMaster (-1 and -2 models) or Severe Duty (-3 and -4) 1-piece forged stainless steel valves with swirl-polished heads, 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, Manley 7° Chrome moly (-1 and -2 models) or 10° chrome moly (-3 models) retainers, keepers and pushrod guide plates. -4 models have 10° titanium retainers.

Head Gaskets: Fel-Pro 375-1017-1 or equivalent
Pushrods: Requires heat treated pushrods
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)