Related Photo Galleries
Here's a correct Hi-Po valvetrain. Note the fewer coils of the main spring, along with the flat-wound damper spring inside. The hardened retainers are thicker than the standard 289 retainers, and of course you can easily spot the screw in rocker arm stud. Finally, the Hi-Po heads use cast-in valve spring seats for high rpm stability, but we'll get to that in our cylinder head section.