Magnum Blocks are designed for general HP use and entry level racing. These blocks are a heavy duty 5.2L (318) Magnum (P5153579) or 5.9L (360) Magnum block (P5153452). These blocks have provisions to work with all stock Magnum components (i.e. 1992-2001 5.2L and 1993-2003 5.9L w/ crank trigger for MPI, stock style hydraulic roller camshaft, etc). These blocks come with the stock bore size for a 5.2L or 5.9L Magnum and are honed to size for use with stock pistons. These blocks have an extra oil hole from the camshaft up to the deck, so they can also be used with "LA" cylinder heads (if desired). This extra oil hole is covered up by the Magnum head and head gasket when it is not needed (w/ Magnum cylinder heads). The 5.2L block can also be used as a "LA" 318 block with a flat tappet camshaft and LA style heads. The 5.9L block can also be used as a "LA" 360 block with a flat tappet camshaft and LA style heads. These two blocks have a Siamese bore design. These blocks must be used with tappet retainer kit P5155275 (available separately) w/ the OEM style hydraulic roller camshaft since the stock stamped spider retainer will not fit in the valley of the block.