When ordering custom pushrods, the best method is to use a checking pushrod and physically measure the required length with a 12-inch caliper. Note whether the pushrod tip has an oil hole, which introduces error in the effective length. If the pushrod features a cup end configuration, measure the overall length minus the cup depth to determine the effective length. Inform the pushrod supplier of the measurement, and the method of measuring. Choose a pushrod wall material suitable for the spring loads, and make certain to specify the correct tip size to match the rockers and lifters being used.