There was a time when forced induction was mostly relegated to track-prepped cars. But as time marched on, technology improved and boosted engines became far more reliable. When GM introduced their LS line of engines, people were blown away by their power potential, and once gearheads started bolting on blowers (both roots and centrifugal variants) and turbos, the power numbers shot into low Earth orbit. Of course, that was shortly followed by guys finding out the limitations of the stock LS parts. Cast cranks and hypereutectic pistons can only take so much, so the aftermarket responded with stronger forged parts. That smoothed things out for a while, but eventually the stock LS blocks began failing under the increased pressure. Enter the GM LSX iron block. Sure, it came with a weight penalty, but it made up for it with good old boost-wrangling strength.
Chevrolet Performance saw the trend towards forced induction and decided to offer up crate engines for LS fans that wanted to go the boosted route. There are two flavors of boost-ready crate engines to choose from: the LSX376-B15 (PN 19299306) and the LSX376-B8 (PN 19260831). The B15 variant (good for up to 15 psi of boost) comes filled with forged internals and is topped with killer six-bolt heads, while the economical B8 version (rated up to 8 psi of boost) ships with simpler internals and standard LS3 heads. Both have 9:1 compression blower-friendly forged pistons and the newest version of GM's LSX iron block.
So, you have a stock GM LS engine and are cravin' some boost? Well, lots of people slap on blowers and enjoy many trouble-free, fun-filled miles, but they really are pushing things. First off, a stock LS3 engine is already in the 11:1 compression range, not exactly boost friendly, especially on today's pump gas. Second, the hypereutectic pistons get unhappy real quick if there's any sort of detonation. Lastly, the stock rods and crank are perfect for what they were originally designed for, but that design didn't include gobs of boost-fed power. Again, 5 or 6 psi of boost—if properly tuned—shouldn't pose an issue, but hot rodders are known for pushing things in search of extra power. After all, one or two more psi shouldn't cause a problem...right?