1974 Plymouth Duster Restomod

Hey where did you get your rear coil overs from? were they pretty stiff ?I'm looking to stiffen up my 74 we almost have the same set up suspension wise do u have a part number or link thanks diggin the build just got done with my 410 stroker 4speed love it . Keep up the good work glad to see the young guns like myself go at these abodies