I am running the recommended spring for my stock engine. It definitely quiet it down and smoothed out my idle I haven't hooked up a gauge to see what my fuel pressure is. I would recommend it

The install is easy I ran the black springs in the truck with less mods. And ran the
Mid spring in my other. The throttle response all of them was better and a little more crisp. I will be buying a third set. Worth the small price!

I installed the gold spring on my 02 7.3l and wow. It has a much quieter idle as well when in high rpms (above 2000rpm) and throttle response is amazing! I went out and tested it. Floored it at a light and it took off quick! Much better than before.

Great kit with quality parts. So nice to have a choice of pressure.

Noticeable difference in throttle response crisp and clean !

Used gold spring. Quieter injectors and smoother idle.

At 225k my fuel pressure was getting weak and this fixed my issue I recommend this product

I Installed the black spring when I resealed my fuel bowl. Idle quality is up, throttle response is up. You'll really notice a difference when you lay the hammer down on a hot tune. It's also super easy to burn up pumps if you don't use these wisely. If you're looking at this kit to cure low fuel pressure, don't do it.

So nice to find quality parts, thanks guys for keeping me away from eBay junk and the price is better to boot.