I own a Lincoln but i just bought a Cadillac for my brother. Its getting a new engine on top of other things. My problem is that it has a blown rear air bag. With my Lincoln I just riped some springs off a crown vic. But being new to Cadillac's I didnt know if i was going to be forced to buy one of the expencive bonversion kits online.

A 93 DeVille does not have air bags in the back, it has air shocks. You can purchase them for the same price as normal shocks, and it is a fairly simple repair as the rear is not coil-over-spring design, rather the spring is located further inward on the control arm.