ERL can make your OEM LS/LT block into a bullet proof foundation that can handle 1,500HP plus! The factory block is machined with ERL's Superdeck Sleeving System which includes a truss design that connects each pair of head bolts through an aluminum truss. This truss allows the load to be shared across the deck surface minimizing deck deflection. It includes ERL's solid doweled billet main caps and the addition of 5^th and 6^th bolts for aftermarket heads. The ERL sleeves are significantly longer and thicker than stock sleeves, this allows for up to a 4.125 stroke and a 4.185 bore. See more at: http://www.erlperformance.com/product/erl-turbo-extreme-race-short-block-package-m5-ls-427-m-lc-pa/