Easiest is the rear servo port. From my research the factory often used that point on hd vehicles with that option. You can ask, read, research till your eyes and ears bleed, everyone will have the absolute answer on why you should or shouldn't put it where ever. Before the cooler, after the cooler, here, there, everywhere! I run mine there simply because it was an easy tap, and from my research it's good enough for me. Put it where ever makes sense to you, regardless of whether it requires easy or more involved plumbing and rest easy.