The best replacement for 4 link is ladder bar.

The best alternatives to 4 link are rated as following:
★★★★★  ladder bar
★★★★★  3 link
★★★  leaf springs
★★★  irs
★★  5 link
★★  radius arm
★★  trailing arm
★★  torque arm
★★  triangulated 4 link
★  3 link suspension
★  leaf spring
★  caltracs
★  radius arms
★  4 bar
★  parallel 4 link
  swing arm
  triangulated
  long arm
  stock suspension
  double triangulated
  ladder bar suspension
  3 link rear suspension
  truck arm
  ladder bars
  forward 4 link

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Speaking about 4 link, one probably shouldn't forget about air bags.

Other search terms related to 4 link and their ratings are:
★★★★★ air bags
★★★★ leaf springs
You have in mind a companion for 4 link and it is not yet here? Propose!



Google Trends

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4 link
ladder bar
3 link