As cylinder pressures, springs pressure and rpm increase, the stress on your factory pushrods increases far beyond the level of stress your factory pushrods were designed for. If you are above 500hp with your ISB you need to upgrade to the heavy duty pushrods. Heavy Duty Steel Pushrods for over 500 HP good for up to 750 HP. Anything higher than 750 HP requires the Extreme duty pushrods which we also sell.
**If you need valve springs and pushrods we also have a package deal from Hamilton Cams for 103lb Valve Springs + Heavy-Duty Pushrods or Extreme Duty Pushrods + a FREE valve spring tool. Please contact customer service to ensure correct fitment on your truck: 216 408 6455**