Most pump makers will tell you that they would like to see a filter before their pump. That's to help protect them from the junk some customers have in their tanks. If you know your tank is clean, and you still have a sock or shower head on the pickup, I wouldn't bother with an in-line. In fact, why even have an in-line filter? How inconvenient is that to have and service? If it clogs, your left by the side of the road with a filter you can't change without tools. If your using a Carrier, the best place for that is the engine compartment, and the best filter to have before it is a fuel/water separating filter. I have a new Racor FPG-200 that I'm letting go for cheap if your interested in that. Whatever you do, use a spin on of some kind so your not stranded.