Upper Radiator Hose Pressure??

I would also recommend a couple of things. Number one is to use the pressure cap that the factory recommended with a cooling system in good condition. For most Chrysler products from the era ran a 16 psi cap. Like said elsewhere don't assume that new means good. Lots of defective stuff out there so test it your self before you trust it.The higher the pressure, the higher the boiling point. The reason that cars overheat with no thermostat and a bad cap. Use a high flow thermostat that has a large bypass hole in it. This will prevent a stuck thermostat from harming your engine from an overheat condition.