Polaris diesel 455 upgrades?

[400exrider707]

I have a couple guys I'm trying to help out with their older 455 diesel Polaris'. I know I've read a write up out there before about how to turn the pump up on these guys, and it's supposed to make them a lot more user friendly and easier to ride. I've tried searching for it with no luck. Anyone know what I'm talking about or know where to find said link?

Thanks guys.