Hey guys, I'm looking to add a lift pump to my truck. I have searched endless threads on here about them. One thing I can't seem to find or figure out is why the centrifugal pumps don't seem to work as well as the positive displacement pumps. I have been looking at the KD and TSS pumps because they are centrifigal mag drive pumps. These seem better because with the positive displament pumps, when the fuel is not needed by the inj pump, it has to go over a relief valve and back to tank which adds air and heat. The centrifugal drive will add some heat and air, but seems like it would be less. The numbers keep showing that the positive displacement (Edelbrock, Airdog, Holley..) provide more power. Anyone figured out why that is? Why does the extra pressure at the injector pump help so much? I was looking at ordering a ITT/Jabsco pump or a KD to try, but don't want to if they don't work. Here is the Jabsco pump Here and Here