If the front end is slammed, then the front air bags are shot. They should be able to hold air for a while. And when you have leaky bags, the compressor is probably dead or on the way out. It's had to compensate for leaky bags for who knows how long, so it's surely been overworked. When/if the compressor runs, you'll be able to hear it if you listen for it, and you can watch as the car raises up.
Personally, I'd repair the air ride instead of swapping to coil springs. I don't know exact cost figures, but I don't think you save all that much with coil springs. When repaired correctly, the air ride system will last for a long time. And I think the air ride is just a cool feature that helps make the Mark VIII what it is. Just my opinion
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Tony - St. Louis, MO[/font]
1998 LSC - Toreador Red/Light Graphite
1989 Mustang LX 5.0 - Scarlet Red coupe