Air suspension deflates
Look into a conventional suspension conversion.
The Rainier (and its siblings) had air bags in the rear. I ran across a UTube video showing how to repair them......look for the video. Seems like they leak at the top.....since the air bag helps support some of the rear weight, I don't think there is a simple fix like just removing them. Since there are lots of companies making air bags for the "low rider" crowd, you might be able to substitute some of the newer bags on your vehicle.
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