1985 Eldorado rear suspension
 

I just purchased an 85 Eldorado and it looks like the rear end is sitting pretty low. It has the electronic level control but I'm thinking its not working. Can I just replace the rear suspension with a pair of air shocks? I don't know how successful I'll be trying to replace the compressor/dryer etc. with a 30 year old car.

I did that on my seville no problems just adjust to the ride height you want. I'm running 50 psi if you run higher pressures its possible to break a shock mount depending on there condition.