Sorry I can't measure the pressure, I already installed the shocks.
They are stiffer than the old & weak OEM shocks, as expected. I'm sure the old shocks were not a standard for the pressure. These shocks have superb mounting hardware as well.
I would definitely buy them again. They took a lot of pressure off of the deck as compared to the NAPA shock. The NAPA shock is very good quality- BUT they are designed for a different, non Pantera application. The Wilkinson shock is designed for the Pantera.