I have a seirra 1999 4x4 with the 5.3 that I'm pulling out to put a lsa ls3 with the super charger on it so it should push around 650 Rwhp with my mods. What's the biggest race or walbo I can put In it. The lsa fuel rails are a dead end system as well so I'd hate to burn the pump up. Any help would be amazing Guys

 

Walbro 400/450 is the standard option these days. 's basically a drop in the stock fuel module bucket minus a little bit of dremelling. ItFor proper operation though you will need an aftermarket fuel regulator.

 

I prefer dual walbro 255s. It is a little more complex setup but the walbro 255 reliability has been proven over the last 10+ years. I might jump on the 450 bandwagon once it has been proven to last, IMO it is just to new to say that.

Everyone else will say 450. I stick with what i know works.

 

On that that would my stock fuel lines be big enough to feed it ? Where I can just put a regulator on before the lines on the blower ?

 

stock lines should be good to around 1000 on gas with enough pump pushing

 

Sweet so just buy some line adapters and a regulator and the 450

 

Yes but make sure you upgrade the wiring going to the pump too, the stock wiring wont like that much draw from a big pump