Zach Archer had already tried vintage Corvettes, Camaros, Mustangs, and modern performance cars, and none of them stuck. So a friend at DI Motorwerkz stopped advising and started building, and what came out the other side was a 1969 Chevelle carrying a claimed 740 horsepower from a modern crate big-block that leaves the factory rated at 627. Read on for what the LSX454 actually is, why it is not the big-block your father argued about, and what it takes to find another hundred-plus horsepower.