408 ci LS Short Block for NA Street - Seasoned GM Block & Callies Compstar 8-cwt Crank

This short block is intended to be used in a naturally aspirated build. Its design is very similar to our 6.0L turbo LS short block. This NA version has a stroker crank for more displacement, flat top pistons for a little bit more compression and a slightly different hone finish on the cylinder walls. Going to a 4.000" stroke with a 4.030" bore diameter brings us to 408 cubic inches. Our standard recipe NA engine builds with this short block typically fall into the 675-750 horsepower range depending on cam selection and other variables. We call the 750 hp cam "All of It".  In our opinion, a seasoned block that we have gone over with our CNCs is a better foundation than a new block new from GM. It certainly offers more value. We push these seasoned 6.0L blocks well over 1,000 hp with no problem.  The Callies Compstar center counterweighted crank with stock stroke brings a lot to the party.  It's increased stiffness and reduced harmonics minimize flexing thereby protecting the block, bea