Air Bag Helpers on a 4x4?

[72longbed]

Don't know if this has been covered yet, but has anybody ever seen or used an air bag setup in the rear of a 67-72 4x4 as a supplemental helper?

Ride-Rite makes a few kits and I have been thinking of retro'ing one for my truck. The Tough Country springs don't really have the carrying capacity of much more than a light 1/2 ton.

Any ideas of input would be great.

Thanks,
72longbed