Well, I had a Fuel Preparator on my L10 Cummins (300 hp) 1987 Peterbilt years ago and it helped a bunch I thought. It was, I believe, the grandfather to the FASS deal.
http://www.pureflowairdog.com/fuel-preporator.php This is a more modern one than mine.
I was told the big deal was that it gets all the air out of the fuel. Normally you're injecting kind of a foamy fuel. With this system you are injecting just fuel. For a pick up, IDK if it that much $ would be worth it though. Maybe if you pull or carry much with it. If it's just basically a commuter type use I wouldn't bother.
Also, I think mine was just an additional pump. It didn't replace any other pump.
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OK, I'm over it. Where's the beer?