I don't know if Tri-City Competition still makes their custom Launcher leaf springs that a lot of Stocker guys have used.

"A long time ago" the father ran one shop (in Michigan?) and the son ran another in SoCal. One specialized in the suspension part of the business and the other did engine work, IIRC.

EDIT: Old thread might have some info, if you're interested: https://board.moparts.org/ubbthread...-tri-city-leaf-springs-still-around.html