I have a 1955 Second Series Truck with a 1979 Camero front end. The steering box is from the 79. I have replaced the power steering pump three times as I only have power steering intermittently. It seems that the power steering works good when it is cold or on the highway. Not so good when the truck worms up and the RPM's are low. Could it be the steering box? Is the 79 Camero full power steering or is it just assist power steering? Thanks in advace for any help.