Now in its third iteration, World’s continually upgraded MERLIN cast iron block is the perfect foundation for any big block Chevrolet engine assembly. Made of a high density iron and manufactured to QS-9000 specifications on just two fixtures to eliminate tolerance stacking common on production lines, the MERLIN III can be bored to a maximum of 4.625” and is clearanced for a 4.375” crank. With a reinforced bottom end featuring 4-bolt splayed main caps, the MERLIN III can handle serious horsepower with complete reliability. It’s an excellent all-around value too!

Material: High Density Cast Iron
Deck Height: Standard 9.800"
Deck Thickness: .600" minimum
Cam Bearings: Standard Chevrolet
Main Bearings: Standard Chevrolet
Camshaft Location: Stock
Lifter Bores: Indexed (stock .8437" bore)
Bore: 4.240 (hone to 4.250") or 4.490 (hone to 4.500")
Maximum Bore: 4.600"
Cylinder Wall Thickness: .250" at 4.600" bore
Water Jackets: Expanded for better cooling
Lubrication: Priority main oiling system
Filtration: Integral mount for spin-on filter
Oil Pan Rails: Solid (stock width)
Crank Clearance: 4.375" stroke
Main Caps: 4-bolts splayed, nodular iron or billet steel
Fuel Pump: OEM mount
Starter: OEM mount
Motor Mounts: Dual (front and side)
Cylinder Head Holes: Blind tapped to prevent leaks
Weight: Approximately 270 lbs.