ss springs rear shocks...info needed

so I called the vender where I bought the ss springs, and asked the about the mp shocks that they recommend to use with thoses springs ... the could not tell me the extended length, and told me to called mopar direct... witch I did, the could not either, told me to put my old shocks on pull them all the way out see how far it is to the stud then ad an 1 1/2 to that measurement.. anyone know what shock will work...looks like 24 1/2 extended is whats needed....