What is there to gain by using aftermarket rocker arms?
The small-block Chevy engine used stamped-steel rocker arms since its inception. They are light, strong, reliable, and adjustable. If you aren’t modifying your engine with a high lift camshaft there is no need to replace the stock rockers. The stock rocker arm ratio is 1.50:1, meaning that the rocker arm multiplies the cam lobe lift by a 1.50 factor. Thus a cam with a 0.300 cam lobe lift has a valve lift of 0.450 inches. A 1.60:1 rocker will provide 0.480 inches of lift at the valve on the same cam. Going from a 1.50 to 1.60 rocker ratio though will reduce the RPM at which the valves float. To maintain the same valve float speed, you must increase the valve spring pressure by 10%. Still, switching over to 1.60 ratio rocker arms is a good and relatively inexpensive way to get some more power (10 – 15hp) from your engine. Going beyond a 1.60 ratio can be expensive and will most likely require different pushrods in order to maintain correct geometry. Replacing the stock rocker arms with a
