a lift pump is what supply the injectors with fuel pressure, a larger one will not do anything unless yours is weak. not sure the SD has a spring you can mod to get more fuel pressure.

 

Where would the spring be at? If it even has one.

 

in the fuel pressure regulator, its been a while since i looked at one in a SD but its different then the OBS which i know has one.

 

The spring is located at the bottom driver side under your fuel bowl. You can by a heavyer spring for 10-12$. Its a quick mod. Also you can pull your fuel pins out and drill one of the holes out from an 1/8 to a 1/4 but I wouldn't recommend doing both holes on the pin unless you are tuning a heavily mod truck

 

None of that is going to do anything for making more power unless he has serious fuel restrictions.

 

good to know what would be the best rout to get more fuel?

 

You need custom tuning, if you already have that then you need injectors, the injectors in a powerstroke only hold so much fuel to inject. You cant put more fuel pressure or flow to them and expect more power.

 

Ok in the e99 doesn't it come factory with single shot injectors and in the later it has double shot?

 

No the E99 came with AB code injectors which are 120cc split shots. The 99+ came with ADs that are 140cc split shots

 

Ok I knew there was a difference just wasn't sure what. Can they just be exchanged. Also I heard the IDM is smaller in the e99 and if you get bigger injectors it can melt the plug to the injectors and ruin them. Or is this another rummor