58 CADDY HELP

a guy i work with has a 58 cadillac with factory air,is there any way he can control the lift on it?the problem is that it lifts up all the way and rides bad.as of right now its all the way down when he shuts it off and all the way up when he starts it.

im not really sure how its setup on that car but most of the time the valve is right on the bag wit cars like that. i know lincolns are liek that but not sure wita caddy. just bypass the wiring and make your own switches get a new compressor and tank. then again i could be completely wrong

the compressor is engine driven on this car