I have a 71 Elky which is currently equiped with rear air shocks. I just replaced the front shocks with Edelbrock IAS shocks which I am very pleased with their performance. I want to know if I choose to replace them what the advantages/disadvantages are to air shocks. Should I just get IASs for the rear too? Thanks for any input. - Jeff

The only advantage to an air shock is if you routinely haul a heavy load or a trailer with alot of tongue weight. They will raise the rear to level. You will not find the level of performance with an airshock that you have with the IAS.
Does your Elky sit too low in the rear if you don't have your airshocks pumped up? If so, replace the rear springs when you install the new Edelbrocks. If you want the raised rear end look , or actually use your Elky for hauling a load, get a set of airbags to go inside the springs. along with the IAS shocks.