Rolling forces?
We are talking about weight transfer from one side of the vehicle to
another, in a hard cornering situation.
No, the Cadillacs not a performance vehicle, but the Vanagon isn't
either.
Neither of them was ever intended to be.
I highly doubt that you could ever exert enough G forces in a Vanagon in
a corner to cause a big enough difference in the pressure in the air
bags to make a catastrophic difference in the suspension from one side
to the other, without laying the Weeble on it's side.
I personally would rather have the bags tied together, so in the event
of one of them failing, the van would drop to it's original ride height
evenly, without laying to one side like a dead carp.
The intallation proceedure is one I have made many times ( air shocks,
air bags) with excellent results, no failures, no suprises.

Later,

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Terry 85 GL