Fuel System Upgrades
Thread Starter
Staging Lane
Joined: Jul 2020
Posts: 51
Likes: 3
From: Southern Minnesota
Fuel System Upgrades I have an ls1 that im building on and will have just shy of 500 rwhp NA. I have 42 lb injectors. My questions are 1.) can the fuel pump be replaced with an inline(external) pump or does it have to remain an in the tank style when upgrading? Also do i or should i get an manually adjusted aftermarket fuel pressure regulator? or is that a requirement?
TECH Fanatic
Joined: Jan 2022
Posts: 1,034
Likes: 468
From: Seattle
External fuel pumps are a lot louder and noticeable than the in-tank ones, and most EFI systems place them in the tank. An added benefit of being in the tank is that the fuel helps keep the pump temperature down. Is your fuel system currently a return or returnless setup?
I've been told that the feed and return lines on the 4th Gen FBody can support up to 1000hp and as far as fuel pumps go you have in the tank pump options that can support 1000+HP. On my 99 car I went to an external pump for ease of pump changes and the feed and return lines are now 8AN which will support my fuel demands when I'm able to make the move to forced induction and methanol. The FPR is fed from the back of the fuel rails with a return line to the tank. The fuel pump will most definetly be louder but chances are it will be muffled by the open headers and shortened exhaust tips..
I'll also add that you should post this in the fuel injection section as you might get more responses there.
I'll also add that you should post this in the fuel injection section as you might get more responses there. 
Just shy of 500, assuming you don't have bigger plans down the road, I'd just do the Racetronix 255 and call it a day. Easiest drop in setup and can just use all the factory hardware including the in tank regulator.
