Thatguy69,
Are you running a Waterman pump also? I realize it's overkill for my needs, but I was already using a billet front cover and planned to re-do all of my fuel lines with stainless braided lines & AN fittings, so I went ahead and got a Sprint 400......Currently I have about 500 miles on the truck, initially the fuel leak fairy was visiting me quite often, but once I got everything tightened down and the leaks stopped, I could not be more happy. I was dead set on a mechanical fuel pump, and had previously used a Fuel Boss, and that was ok.....but even with minimal tension on the cog belt it was still causing premature wear on the seals in the pump and some of this was likely due to how low it was mounted and the dirt & debris it was collecting from driving. At idle, I am seeing 60 psi, and while driving I am seeing 80-95psi.....It will hit 100 psi in higher RPMs, but normally driving is around 75-80psi typically. I am still running the factory fan, but simply spaced my fan about an 1/8 of an inch back further towards the radiator with a large washer and this has been good so far, clearance is tight, however I still have about 1/2 an inch between the pump & fan blades and have never had an issue with the fan blades touching. I am pleased with how well it holds a prime and starts up so far. I do plan to install a one way check valve in it once I have time, this was done on another build and was beneficial in keeping prime, but surprising I haven't really needed it yet. I have noticed that the increased FP has really helped with throttle response and even tamed the surging/bucking a little (stiffer throttle springs helped the most). I mention all of this because I'm not sure too many people are using a Waterman style pump on a daily DD and was curious as to what other folks experience has been.