Technical Specifications of...
Merlin X Aluminum 16° Cylinder Heads

Material: 355-T6 high density aluminum alloy
Valve Seats: Steel intake, hardened steel exhaust
Valve Guides: Bronze
Guide Plates: Standard big block guide plates must be modified
Valve Spring Seats: Machined for 1.640" springs
Valve Size: 2.350" x 1.830"
Rocker Arm Studs: 7/16" screw-in style with hex shoulder. Furnished with assembly
Exhaust Flange: Stock port location and accessory bolt holes
Included In Base Assembly: Manley RaceMaster (-2 models) or SevereDuty (-3 & -4 models) 1-pc forged stainless steel valves with swirl-polished heads, ring & band style (-2 models) or PC style (-3 & -4 models) valve seals, 1.550" ( -2 models) or 1.640" (-4 model) valve springs, Manley 7° chrome moly (-2 models), 10° chrome moly (-3 models) retainers, keepers and pushrod guide plates. -4 models have 10° titanium retainers
Recommended Installation Items:
Head Gaskets: Fel-Pro #1017-1 or equivalent
Pushrods: Requires heat-treated pushrods
Spark Plugs: Accepts 14mm .750" reach, gasketed. Accel 416 or equivalent. Heat range may vary. Consult with engine builder.
Intake Gasket: Fel-Pro #1211, Mr. Gasket 121 or equivalent
Exhaust Gasket: Fel-Pro #1410 or equivalent
Head Bolts: 10 longer than stock required (World #832015-10)