So I am getting ready to put a gen 3 5.3 with a 4l60E into a 1989 Pontiac Firebird Formula that originally had a TPI 350. I know the 5.3 needs 60 psi of fuel pressure. I already have a corvette in line fuel filter that should have built in regulator from what I have read on the forums. I'm already going to be dropping the fuel tank and replacing bushings on the rear so while I have the fuel tank out of the bird, is there any way for me to dissemble the in tank fuel assembly to put in a upgraded fuel pump to achieve that fuel pressure so that way I can just use my stock fuel gauge with the potentiometer on the assembly? if anyone has done this, then what fuel pump should I get? or if anyone has any recommendations on how I should tackle this id appreciate the knowledge on this situation. I love the look of the original gauges and would like to keep them in and functioning.

 

With the tank out the pump access becomes easy. If your swap is staying under 400hp than a Walbro 255 will work just fine. You don't need to be at 60psi. Most LS stuff targets 58 but there is a range. The C5 filter/regulator combo takes away any guessing. However, If you're running a dedicated regulator start at 55 and go from there. Spend some time reading the stickies at the top of the LS swap forums. You're certain to have more questions (like using your stock gages) and a little reading will answer most, if not all of them.

 

Okay sick thank you that's exactly what I needed. ill also check those threads out for that additional info

 

go on rock auto and buy a new sending unit.
theyre like $40 right now.

install the new pump into the new assembly and be good for another 100k miles.

also, where in az are you? im by i17 and bell road..

 

I always recommend 38 to 40psi baseline fuel pressure on everything since the 90's.
Reduced fuel pressure has all benefits: reduced fuel heating, reduced voltage drop, reduced current draw, reduced stress & wear/ tear
increased fuel flow from the pump, increased pump life span

The ideal V8 injection system uses an injector target approx 25 to 35% duty cycle max prior to peak torque, for injection timing window of 290 to 230 Degrees before top dead center compression, this is near peak piston velocity and induction has the highest kinetic energy which can have massive boost to mid-range torque 20% sometimes.

 

My LS swap is running 34psi baseline fuel pressure


22psi of boost 610rwhp dynojet that is 54psi of fuel pressure in boost and (34 - 7) = ~27psi of running fuel pressure in vacuum
Low fuel pressure enables large injectors with much longer idle pulses , which drastically improves tuneability for low speed and engine smoothness when using huge injectors

This is a tuning secret. Nothing to see here nevermind

 

Im over in Prescott AZ. about 1 1/2 Hours north of the valley

 

Prescott AZ

 

That is badass. I'm going to have to learn more on fueling then. I was under the impression that any of LS/LT engines should have around 60 psi at all times. Always able to learn something from others when it comes to this stuff.