Merlin Grumpy Iron BBC Heads
Up for sale is a legendary set of World Products Merlin heavy-duty cast iron cylinder heads for Big Block Chevy V8 engines. These feature the highly sought-after, cast-in Bill "Grumpy" Jenkins signature logo. Built for ultimate rigidity and durability, these heads are virtually bulletproof and perfect for high-horsepower street, strip, or marine applications.
They are designed for maximum airflow at high RPMs and work perfectly on larger-displacement blocks (454, 496, 502, up to 540+ CID).
Technical Specifications:
Material: Heavy-duty, high-density cast iron
Casting Number: 04301 / I-043 series
Intake Port Style: Rectangular port
Intake Runner Volume: Large 345cc high-flow runners
Combustion Chambers: 119cc open chamber design
Valve Sizes: Massive 2.300" Intake / 1.880" Exhaust
Spark Plug Style: .460" reach, 5/8" hex tapered seat
Fitment: Mark IV, Gen V, and Gen VI BBC blocks (Note: requires correct head gaskets when converting to Gen V/VI blocks to seal coolant passages)
Condition Notes for Buyers:
Due to the massive 2.300" intake valves, you will need to check your piston-to-valve clearance during mock-up. Perfect upgrade for anyone looking to build a bulletproof 650–850+ horsepower big block setup without the warping risks of aluminum heads.
