myowneq...IF you don't yet have the Firestones or can't get a refund on them, consider the AirLift 5000 with remote. I have one on my Tundra.
You have an on-board pump mounted under the bed, and a wireless remote in the cabin (clips on the visor) with digital readout that you use to set the airbag pressure, from 5 to 100 lbs. There's NO plumbing to the inside for gauges, no tubes, no connections, no leaks, no worries.
The pump sensor will continuously and automatically adjust the air pressure, either running the pump or venting air, based on the change in load, even with as little as with me getting in or out of the cab, and I weigh only 175.
Regards, BGood