link length?
 

Is there an advantage to having longer links over shorter links?

For one, longer links mean longer radius so your total wheelbase doesn't change as much when your truck cycles it's suspension. This has numerous advantages, easier shock placement, less axle clocking during flex, easier 4 link design, more allowable flex when using a triangulated design.

Setting up 4-link suspensions is part science, part art, but a lot of reading!