I have a MP112 going on my 2004 Sierra and needing help with fuel pump upgrade and injector sizing. I’m shooting for 500 crank HP. The supercharger kit came with 42LB injectors. Will these be big enough. Also, what pump should I upgrade to. Thanks

 

I think they came with a Warlbro 255 pump.

Is this a different truck? Didn't you have a Kenne Bell?

 

I ran the 8.1 marines (I assume that is what you have) for a while on mine at lower boost levels with a Walbro GSS340 (255lph). When I started pushing it, I swapped to Deatschwerks 60lb (72lb at our pressures). I’m still running the same fuel pump, with a Kenne Bell Boost-a-Pump. I am at the limits of it, and will go to a Walbro 450lph or 525lph if I push it further.

 

This user is BIG_KID, not BigKID.

 

will the GSS340 swap in place of the stock fuel pump and play nice with the stock regulator and all that junk that’s in the basket…

 

LOL
didnt know there was more of me…

 

From what I recall, the 340 is a direct drop-in. It will play nice with the regulator in the fuel module. If you start upping the boost, you will likely see some pressure drop at high RPMs, but it can still work fine. I would likely do a hotwire upgrade for the pump - either Racetronix or make your own.

Look up the other BigKID’s build thread - you’ll like it.

 

Those should be up to the task, if you want more just buy a set of fast 65’s. I ran the fast 65’s in my supercharged 5.3 and made 640 tire with them.