[Bowtie67]

4 link setups I wouldnt think would have a bearing on heavy loads, what does have an affect is the spring rate, on the rear of a truck the average coilovers springs have a 400lb spring rate if you going to need to haul heavier loads go to a 500lb spring rate. At the same token why would you change to a different rear suspension than stock if it is for a working truck. I could see changing it to be different or for performance reasons. If your changing it to hall heavy loads then put load helpers on or get a trailer that will hall the heavy loads. Increasing spring rate, installation of help springs or installing super duty leaf springs will make this ride a lot stiffer when empty. JMO