I don`t really recommend a 4 link for the street , it requires coil over shocks , & the shock mount Has to be reinforced to take the load , the leaf springs are removed & the frame in front of the diff has to be modified & plates added to locate & adjust the 4 link bars , you also need a track bar to keep the diff located square under the car as the 4 link has no resistance to side movement , often the feul tank has to be moved or modified to allow enough clearance for the track bar & coil over shocks
my preference for street use is a Ladderbar system , it can be use with the leaf springs & floaters or you can replace the leafs with coilovers which again requires a track bar , I have built 2 street cars with ladderbar systems & the traction is awesome , I retained the leaf springs in both cases so cornering was good to & if a rod end fails the leaf still keeps the diff in place