From my stock of Cadillac parts is this air ride valve from a 58 - 60. Unfortunately, I do not know exact application. I think it is for a 58. It has part number 5540458. This valve appears in decent condition and the arm moves freely. Since the valve is 65 years old I am selling it as-is for a core to rebuild. I have other air ride valves available that I haven't identified yet.