My 255 has fell short and was wanting a slight upgrade without building a complete new set up with an aftermarket regulator. I wonder if the stock regulator will be overppowered by the 400?

 

From i read on ls1tech it flows too much for the stock regulator

 

Time to go for a full fuel system upgrade. Time for dual pumps, Hobbs switch, boost referenced fpr, and fuel rails.

 

Do you have a boost a pump? I have read also the stock regulator won't work. I'm going to end up doing dual 400's with a -8AN return.

 

Currently I have a 255 and 75lb at 4 bar injectors and M15 nozzle straight meth. I daily the truck so taking it down for a full fuel system rebuild is a no no and money is tight as well. Maybe I will put 2 fresh Walbro's in the stock bucket with a hobbs on the second one. Seems to be easiest and most affordable option.

 

im running stock rails and gutted my regulator and have an aeromotive fpr in my return. wasnt hard at all. duall 255s but the same issue

 

What injectors? That would suck if I went to dual pumps and it did not help much.

 

fic 75lb. he doesnt sell them anymore but they look exactly like the factory truck injectors

edit... i think the ones you have

 

I know people who have ran A1000s with the stock regulator, so if the 400 flows less than that I know you will be fine.

 

i know my 255s had high pressure if checked before the reg, and if you checked at the aeromotive fpr it was correct... as in around 90psi before and 62 at the aero... so if not checked properly im sure it seems ok but there was no way mine was gonna work. after gutting the regulator and drilling out the rails mine is the same at the reg and rail