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!

GET IT PREPPED! For the enthusiast who is planning to assemble an engine in their home garage, getting the block in a RACE-PREPPED state is a no-brainer. Our experienced staff performs important basic operations like: • Deck milling +/- .0025” • Main journal honing +/- .0004” • Cylinder bore plate honing .001” oversized +/- .0005” • Lifter bore honing +/- .0005” • Block hot tanking • Cam bearing installation • Freeze plug installation • Dowel pin and pipe plug installation • Block deburring • Machined surfaces sprayed with rust inhibitor • Protective wrapping

More and more professional engine builders are also recognizing the benefits of ordering race-prepped blocks instead of endeavoring to perform these many tasks themselves. Many have realized that their time can be better spent doing critical assembly work such as degreeing in camshafts and setting up the valve train. By employing race-prepped World blocks the shop’s through-put can be accelerated, and there are demonstrated savings in terms of personnel, shop equipment, space and cash flow. Whether you're an enthusiast or engine builder, save time and money!

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: 4.625"
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.