"LA" Cylinder Blocks
These Mopar Performance cast iron R3 race engine blocks feature process-controlled castings utilizing high-strength cast iron and a computer-controlled stress relieving process. They are 100 percent CNC-machined with full statistical process control and a thicker deck surface with a 6-bolt cylinder head attachment for improved sealing and reliability. The Mopar Performance cast iron R3 race engine blocks are offered in various deck heights in your choice of standard (siamesed-bore) or bore diameters. The blocks have thicker main webbing, an oil pan rail for improved rigidity, and 4-bolt mains in either ductile iron or steel billet. Tappet angles are also available in stock 59 degree or 48 degree to provide improved valvetrain geometry. Get the latest technology for your small block Mopar by using one of these Mopar Performance cast iron R3 race engine blocks.
Limited production of the original 340 Block has made it very difficult to find one in good condition. Why take a chance with a 30-year-old-plus block when you can buy a new one? This new casting includes the original 340 production casting part number with an “M” added at the end to identify the Mopar 340 Block. The block has a few cosmetic differences from the original 340 Block, but it is machined to work with all 340 production components. Special features include brand-new castings made from high nickel cast iron for added strength (not a thin wall casting), 4-bolt main bearing caps, and 340 journal size. It has thicker webbing and pan rail (like the 1970 340 T/A version), a thicker deck surface and thicker bore walls in major and minor thrust directions. Block is rough bored at 3.900" to allow various bore sizes, from 3.910" to 4.080" (finish bore and honing required). Deck height is approximately 9.600". The 340 Replacement Block is ideal for restoration or where racing rules require a 340 block.