This short block is intended to be used in a naturally aspirated build. Its design is very similar to our 370 cubic inch, boost-ready 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". You can watch the video to see this short block do its thing on our dyno as a completed build.
In our opinion, the 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 in boosted builds with no problem using the same parts as this short block other than as noted previously.
The Callies Compstar center counterweighted crank with the longer 4.000" stroke adds cubic inches which are easily turned into horsepower. The extra counterweights bring increased stiffness, reduce harmonics and minimize flexing thereby protecting the block, bearings and rods from excessive wear and fatigue.
Depending upon availability and customer preference, we use either Diamond R Series or Manley Extreme Duty Platinum flat top pistons. These are paired with Callies Compstar or Manley forged H-beam rods to complete the rotating assembly.
These short blocks are quick-ship items. We usually have one either on the floor fully assembled, or have fully machined parts ready to assemble. Click on the BUY NOW button to get to our website to place your order or get more information. You can also call us at 815-725-2727 with any questions.