2003 Sierra 2500HD 6.0L
Magnuson TVS1900 w/ 9lb pulley & 42lb injectors
Stock Delphi in-tank fuel pump
Also has the in-line pump that Magnuson supplies for 03 models only...

I'm not getting enough fuel and leaning out too much around 4500rpm.

What would you do? Upgrade in-tank with Walbro GSS340 and hotwire kit and leave the in-line there? Or upgrade the in-tank and remove the in-line? I do have a GSS340 (pump only) that came with my kit for 04-06 models but it doesn't look the same as my stock 03 in-tank pump setup....there's 2 hoses in the stock pump, only one in the 340...

If I remove the inline and install the Racetronix suggested parts list below, will that be enough?
Pump Drop In - Racetronix - FPM-007 - Fuel Module, GM SUV, High Perf. Type 007
Hotwire Kit - Racetronix - FPWH-001 - Fuel Pump Wiring Harness, 98-03 SUV


Any input will be appreciated!

 

That module and wiring harness to handle the additional current will work in that setup nicely.

 

With the 255 in tank module you have in your link, you will not need a hotwire kit. at least I have not with mine. BUT, i think that you will need more than a 255lph pump. I believe a 400/450 will be needed. I currently have that same exact drop in pump in your link in my 03 and I plan on upgrading to a 450 in preparation for for boost. I will also be installing a hotwire kit when i bump up the pump to a 450

_Zblee

 

I had the same setup on my 2500hd a few months ago. I swapped out the inline since it's a 190 for a 255 and changed the injectors to 60s. (That was with a 2.8 pulley) Now that I have a cam and 2.7 pulley i removed all of it and did an intank 450, racetronix harness and external fuel regulator.

 

Did you need to switch out to 60# or was that just to be safe?

Racetronix said they can set me up with that same unit I linked to but with a 340lph upgrade. I think that's the route I'm gonna go, then take out the magnuson supplied in-line, and upgrade to 60# if the injectors are then the limiting factor

 

The injectors my brother got with a camaro he bought to return to stock, so they were free...lol. With doing the cam I wanted to prepare with all the fueling needs. Not sure if I really needed them but 60s I was told more than once to go with.