I hate to be the bearer of bad news but your sedan leaf springs will not work on a convertible, at least not correctly. A common misconception is that convertibles are lighter because they have no steel roof. The opposite is true as the roofless cars need sturdier frames and body components to restore structural integrity therefore resulting in a heavier car. In fact convertibles are usually the heaviest model in their line-up with the exception of the station wagon and in the case of the Imperials, the limousine. I'm afraid you'll have to procure some convertible springs or have yours redone. Have a nice day. Doug 58 Crown coupe