A one-piece push rod and method of making same is provided which includes the step of swaging at least one end of a hollow tube to define a seat portion having an extended spherical surface for inhibiting interference with a rocker arm socket. Preferably, the tube is characterized by a thicker middle...http://www.google.fr/patents/US5027763?utm_source=gb-gplus-shareBrevet US5027763 - One-piece push rod having enlarged spherical seat
