Tl, a buddy of mine has owned his own rod shop specializing in old trucks for years.
https://www.tricktrucknrod.com
He uses Heidts for his suspensions and built the chassis for my 48 Suburban using their parallel 4 link set up.
Heidts has a universal triangulated kit and a parallel 4 link specific for the 47 to 53 truck.
http://www.heidts.com/part/47-53-che...4-link-rb-108/
And there are other companies that have suspension kits too... Scott's, No Limit, Art Morrison...just to name a few. No Limit is a sponsoring vendor here so be sure to check them out too.