well , i am jumping in here .
i worked on a 58 buick for a coustomer i had a torque tube and a heavy as hell rear axle . to install airride on it you have to remove the trans,tube, and axle and replace it with different parts . we used a th350 trans with adapter , made a custom trans mount anyone can do this . then we put a ford 9 in in it and used a airride kit from airride tech. with a triangled 4 bar set up , this is a little harder , you must have a good welder,anglefinder ( because i cant spell inclimeter?) and be able to make brackets to attach this to the frame because there is no bolt on kit .
for the front this is the easiest part , take out the spring and install the airspring and measure the difference and make a spacer ( included in the kit ) to make up the difference .
now this is the short version of installing this in a 55 -58 buick.
there is many things you MUST understand about airride first , before trying to install airride without bolt -on kit .
no 1 , you must follow airrides specs. on airspring length.
so do your homework first or you will not be happy with airride
proper installed airride will ride , handle ,and look better than a coilover or spring set up !!!!
but i must AIRBAG THE WORLD !!!!!!!!