first off, split dual exhaust only adds to the complexity, cost, and weight of the system. it will still sound and perform like single exhaust.
secondly, if your going to dump it right after the muffler, under the truck...why get a dual out muffler anyway? or did you mean dump it right in front of the right rear wheel?
thirdly, if you DID mean dump it right under the truck...dont. it will resonate and sound horrible at highway speeds. the exhaust gasses will speed corrosion of steel components under the truck, and you increase the risk of poisoning yourself to death.