This externally balanced harmonic balancer is designed to fit most crate engines that require a 454ci-weighted balancer, delivering smooth, reliable operation for street and performance builds. With an 8-inch diameter and clearly marked degree timing references, it makes setup and tuning straightforward. Built for non-SFI applications and supplied with mounting hardware, it’s a dependable, ready-to-install solution for big block Chevy combinations needing external balance.