Stock Fuel Pump MAX HP

[BOOT]

Walbro 255 fits in the stock bucket, gss340

I'll add that to my notes thx!

 

[PlayingWithTBI]

I wonder if the tank would fit or if I could swap the entire sending unit n stuff.

I don't know if they both have the same locking setup on top or if the 2 tanks are the same depth. You can pull both and compare, if different you can always swap the pumps.

 

[BOOT]

About 350 HP with an EP381.

So maybe not even a stock vortec 350 with the current pump?

 

[Supercharged111]

A TBI pump at 5-6 psi is likely more than enough for a healthy carved 350. They flow more volume when the pressure is cut in half.

 

[BOOT]

A TBI pump at 5-6 psi is likely more than enough for a healthy carved 350. They flow more volume when the pressure is cut in half.

It has a mr gasket dial deadhead reg on it and I just got a holley bypass 4-9 psi. I also have a holley red pump I may put on it temp but we'll see, think I'd just put a 10-16 gal fuel cell in the tool box if I go that route.

 

[Supercharged111]

It has a mr gasket dial deadhead reg on it and I just got a holley bypass 4-9 psi. I also have a holley red pump I may put on it temp but we'll see, think I'd just put a 10-16 gal fuel cell in the tool box if I go that route.

Just how much power are you making? That seems like overkill.

 

[BOOT]

Oh it won't be a power house anytime soon but I bet I could tweak this 350 close to 300 and I might put a kit on it for LOLs Eventually it'll get something with more HP but for now I'm just figure what it can take. A low psi red pump n cell would just make it easy n get rid of any tank starvation issues I've herd these can have, if i take it to some autoX type event. The bypass reg is just so I don't burn up the pump or vapor lock, if I go with a vortec high psi pump I'd have to use a diff reg tho

 

[Supercharged111]

Oh it won't be a power house anytime soon but I bet I could tweak this 350 close to 300 and I might put a kit on it for LOLs Eventually it'll get something with more HP but for now I'm just figure what it can take. A low psi red pump n cell would just make it easy n get rid of any tank starvation issues I've herd these can have, if i take it to some autoX type event. The bypass reg is just so I don't burn up the pump or vapor lock, if I go with a vortec high psi pump I'd have to use a diff reg tho

I'd try keeping the stock TBI pump running at that lower pressure.

 

[blackdeathmessenger]

I would NOT go with the EP381.... too much pressure results in wasted gas/oil contamination. I used a fuel pump from a '94 454 truck in my '88 (lowest fuel pressure of the 454's) and I get better economy than with the 381 pump. The pump will live longer and so will the engine. Everyone on the forums tend to overdo things because they don't know any better. I'm running with the stock size injectors and the pump mentioned earlier and am doing just fine. the stock pump (for a 350) is only good for about 270 horsepower at max, and maybe not even that much. The EP377 is a good upgrade from the 386 pump for even a stock 350

 

[Erik the Awful]

The stock TBI fuel pump is barely enough for a stock motor. Use the EP381 or equivalent. It fits the earlier pickup assemblies like factory. The fuel pressure regulator in the back of your throttle body will bypass the extra volume back to your tank. Putting in a higher pressure pump will not result in wasted gas/oil contamination unless you overpower the regulator, and there are plenty of people on this forum running Vortec pumps in TBI trucks to disprove that hypothesis.

Quick science lesson: your pump does not make your pressure, it moves a volume of fuel. The resistance to that flow is pressure, and some pumps have a lower internal regulator than others to limit their flow if the pressure is too high. The TBI pump is low volume and has a lower threshold for bypassing. The Vortec is a much higher volume pump and has a higher threshold for bypassing, meaning that it CAN create more pressure in a fuel system. The pressure regulator on the back of your TBI is what determines the pressure in your fuel system. The only way to get too much pressure is to overwhelm the regulator with enough volume that the return line becomes the restriction. Also, cutting the pressure does not increase the volume, unless the pump or regulator has some sort of funky cavitation or turbulence.

The sending units have a different plug and the fuel line connections are different. On TBIs the 4.3 and 5.7 sending units are the same. I put a new brand-x Vortec pump onto a new brand-x TBI sending unit for my truck for $60. Turned out the TBI was a leaky pile and wasn't capable of handling my cam, so I put a Sniper on it.