LS Fuel Pump

[custodian]

I'm going to change from an external fuel pump to an intank EP381 fuel pump on the 73 C10 with the 5.3LS swap. Will the sending unit/hanger from an 87 work in the 73 tank?

 

[CalSgt]

AFAIK they fit fine, disadvantage is not having a baffle to keep the pump fed when fuel sloshes in the tank

 

[CalSgt]

Really, the ‘87 tanks with baffles are fairly affordable. I think mine were right at about $100 per tank when I did mine

 

[Ricko1966]

Hmm look at this,I think I could fab up a baffle arrangement like this. Click on the pic it's not all visible In the thumbnail.

 

[Camar068]

not sure, but just a thought thats been on my mind. Put that filter/regulator where u can get to it easily to change it. Mines jammed between the frame/rear fuel tank.

 

[SquareRoot]

87 up have baffles in the tank, otherwise identical......almost. The filler neck is smaller so you will need to match the filler hose to the tank, not the truck. Left and right tank are the same, the sending unit is not. If you can afford the extra $100, buy a new tank. Assemble everything outside the vehicle and then just remove and replace. I did both sides on my 85 when I converted to EFI. Your doing it right. Can't beat factory engineering! LMC has the filler hose and anti squeak strips. Rock auto has everything else

 

[SquareRoot]

not sure, but just a thought thats been on my mind. Put that filter/regulator where u can get to it easily to change it. Mines jammed between the frame/rear fuel tank.

Mines on the front crossmember behind the radiator. Right between the fuel hardline and the fuel rail inlet. AN fittings allow a npt port for a fuel pressure guage. Bonus

 

[87chevy_com]

I designed these fuel hats for the c-10 for higher current rated fuel pumps. the stock sending unit terminals can only handle 14 amps... more higher powered pumps draw more. while uncle eddy never has a problem. data sheets led me down this path this setup allows up to 25 amps on fuel pump power wires:

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[Ricko1966]

I'm not sure how many people are going to be pulling more amps than what a stock sender can handle,but another option would be use a stock tbi pump as a pusher pump to an external pump.Thats how VW and Ford do it,probably others also.

 

[87chevy_com]

stock tbi system pressure is like 14 psi? that sounds like that would be a restriction. If you woud be using an internal pump, mine as well get one to do the whole job?

stock pump for stock builds work just fine for the stock sending unit wiring. I ran just that for about 10 years on my 87 with a 5.3 LS swap with ep241 pump (if remember correctly). But, some might want to run a supercharger or turbo or something that needs more fuel and they want to run a walbro 450 pump...

spec sheet for 450 pump

I also wanted to run e85 in my build, this allowed me to do so. e-85 deteriorates and breaks down rubber over time and therefore I ran the flexible plastic fuel line like modern fuel sending units use.

Just another option out there, thats all

 

[Ricko1966]

@87chevy_com no a lower pressure will not be a restriction its how Ford and VW are doing it,a low pressure pump to supply a high-pressure pump so the high pressure pump always has fuel. Kinda like supercharging your fuel pump. Your fuel tank it self is zero pressure and that does not make it a restriction. If the volume were insufficient it would be a restriction. I only mentioned it because someone else( it was you) was concerned about drawing too much average through the sending unit. Pusher pump,pressure pump just seemed like less work than manufacturing your own sending unit for most people.