Stillen Headers + Berk HFCs self-install report

Originally Posted by ChrisSlicks

Thanks. Yes, I understand that under-drive scenario, but Stillen also makes lightweight pulleys that are identical to stock except for weight. I was wondering if they would net a measurable increase due to a slight reduction in rotating mass. I'm guess not, as the reduction is only 3.4 pounds which is nothing compared to the engine and flywheel, not to mention transmission. Obviously for NA it would be better to use the under-drive pulleys.