ive heard about this could someone give me some info on it like what is it? how much is it? what it does? if it gains hp? if so how much?

 

Shimming the fpr raises the fuel pressure, so the injectors fill more completely with fuel before firing again. It isn't so much a horsepower mod, as a smooth operation mod. At least on my truck, I noticed the idle being a little smoother. I suppose there's a hp increase associated with it, too, though it's not a huge amount. This only applies to the pre-99's because their fuel system is different than ours. Here is a pic of the internal components of your fuel pressure regulator, and the different things that can be used to shim it. Here are the steps:
After removing the engine cover, take an initial reading of your fuel pressure at idle by using a tire pressure gauge on the shrader valve on the driver's side of the regulator. You're probably in the 45-55psi range.
Shut off the engine, and remove the large brass nut directly behind the shrader valve. As you remove it, you'll find the spring in the picture. At the other end of the spring is the metal cup that's also in the picture. This cup doesn't have to come out, though it sometimes does.
Shimming is merely increasing the tension on the spring. This can be done a number of ways. One is to simply insert a BB into the cup before reassembly. The option I chose was to use a cap screw like the one in the pic.By inserting the threaded portion of the screw into the spring, then re-inserting the spring into the cup, you've effectively compressed the spring slightly.
When putting the brass nut back on, be sure to get the nipple inside the nut centered on the spring to avoid kinking it. Once everything is back together, recheck your fuel pressure at idle. Ideally, you want to be in the 70-80psi range. If your pressure is still too low, you might need to add a nut to the other end of the screw, which would compress the spring more once re-assembled. To get the screw and nut down inside the cup, you'll need to round off the corners of the nut. I was able to find nylon nuts for this purpose, which made the filing a lot easier. If you want to get the cup out of the regulator, a magnet will pull it out for you.
After a little trial and error, you should be able to get your pressure into the desired range. Don't adjust it over 85psi, or you stand the risk of increasing the wear on the tandem pump.
If, after reassembly, you find the pressure has spiked way up, it's likely that you've kinked the spring by not getting it centered on the nipple. Simply take it apart, and re-assemble.
If you've got all the parts handy, the whole process only takes 10-15 minutes, and the components are really cheap.
This procedure won't make you think you've added a chip, but it's one of those things you tinker with once, and your truck runs a little bit better from then on, forever.
I hope my instructions were clear. If not, let me know, and I'll take another stab at it.

 

will it matter that i have a super chip micro tuner
with it i have 60psi i think

 

Whether you have a chip or tuner doesn't matter. This is purely a mechanical adjustment, getting the pressure back up to what it might have been when the truck was new, or at least what it should have been.

 

Thanks Quadzilla for the instructions. i just did mine in 10 minutes like you said. i'm now at 75psi.

 

If your truck is like mine, you probably didn't notice a huge improvement in power, but the idle is probably a little smoother, and when accelerating, the engine likely sounds and feels smoother.