How much RPM or power? Or does anyone know the limit of the stock ones? usually when people get a set of heads/cam and longer or shorter pushrods are required are people purchasing hardened ones?
You need hardened pushrods when you convert to stud mounted rockers and use guide plates. The pushrods need to be hardened as they come in contact with the guide plates. If your running pedistal rockers, no need for hardened.