Vortec swap with Edelbrock ProFlo4

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2JHead

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Guys,

I went and got a (brand new crate) 96+ Vortec engine (L31) for my -88 1500. I blew it apart and modified the heads for more lift with LS6 springs and Comp retainers and installed a Lunati voodoo 262/270 cam. The engine was toped with a Edelbrock ProFlo 4 MPI system. I now have a couple of fuel system related questions I was hoping you fine folks could help me out with :)

1) I have searched the forum and it seems that I could use the ACDelco EP381 fuel pump for this application. Apparently this is the OEM pump for 96+ trucks? When I look up the fuel pump for 96+ trucks at Rockauto I get a p/n MU1745, a complete in tank assy by the looks of it.
- Am I correct assuming that the EP381 is part of the MU1745 assembly?
- Will the EP 381 fit in the TBI in tank arrangement?
- If yes, should I get the MU1745 anyway to be on the safe side given that I am pulling the bed for this operation?

2) The ProFlo 4 MPI requires 43 psi regulated fuel pressure. Will the OEM TBI fuel hoses stand up to this pressure? This is probably like 3 times the TBI pressure but still kinda low for any given hose?

3) I plan on running an Edelbrock fuel pressure regulator that is designed for the system and conveniently mounts to a fuel rail. It has -6AN fittings. Would anyone know p/n's or where to look for adaptors that would take the OEM TBI fuel lines from whatever they are to -6AN?

Sorry for firing questions left right and center but any help would be very much appreciated :)

I promise build pics!

JT
 

Schurkey

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When I put a higher-pressure fuel pump in my '88 K1500, I used a Delco EP241.

Exact fit EXCEPT for the different-diameter outlet from the pump.

https://www.thirdgen.org/forums/tbi/612473-tbi-fuel-pump-upgrade.html

Mind you, I'm still TBI, so my fuel system is still low-pressure. I have every expectation that the TBI plumbing would take ~60 psi, but zero experience. OTOH, Edelbrock sold a high-pressure fuel system kit for TBI engines, where the OEM computer drove a "Kludge Box", and in turn the Kludge Box drove batch-fire high-pressure injectors. The Edelbrock system required a high-pressure in-tank pump, but didn't include any replacement plumbing--so I guess Edelbrock understood that the OEM plumbing was up to the task.
 

Steve A

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1) I have searched the forum and it seems that I could use the ACDelco EP381 fuel pump for this application. Apparently this is the OEM pump for 96+ trucks? When I look up the fuel pump for 96+ trucks at Rockauto I get a p/n MU1745, a complete in tank assy by the looks of it.
- Am I correct assuming that the EP381 is part of the MU1745 assembly?
- Will the EP 381 fit in the TBI in tank arrangement?
- If yes, should I get the MU1745 anyway to be on the safe side given that I am pulling the bed for this operation?

I would be doubtful about the 96+ module fitting your tank opening as the 96 module includes the fuel level sending unit along with the reservoir housing with the pump inside. Might be able to fit a 96+ tank to your truck though so the MU1745 would be usable then otherwise just a higher pressure pump would work, I would think.
TBI lines are ok but you might want to replace all rubber hoses with new fuel injection hose and fuel injection hose clamps just to be sure. IIRC the TBI hard line connectors are just inverted flare fittings, so inverted flare to AN adapters should be easy enough.
 

PlayingWithTBI

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Will the EP 381 fit in the TBI in tank arrangement?
I put the EP381 in my 88 C1500, it was a direct fit for the anemic OE pump since I'm running higher pressures and flow in my TBI system. I changed the suction sock, cleaned the ground connections, and installed a new fuel filter. Here's a copy from my build spreadsheet with part #s and prices (from 08/2018)

Fuel Pump ADO-EP381 AC Delco 155lph (for Vortec TBI) Summit Racing $69.99
Fuel Filter KNN-PF_1000 K&N Summit Racing $11.99
Suction strainer ADO-TS6 AC Delco Summit Racing $8.99
 

1990SS

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I'm running a Pro-flow on my Big Block......I left the oem in the tank and added a booster pump, post filter put in a regulator with a return and a boost port, another filter and new line up to the pro flow. Works great! Holds 60 PSI at WOT. Only problem I have with this setup is it will starve for fuel on Launch with anything less than 1/2 tank! Oem pump on my truck seems to handle the volume fine.
 

Tim W

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I sorta went through this same thing with my Holley sniper and vortec 383. Instead of throwing fuel pumps at it and hopping it worked it just eliminated the intake pump and run an external pump from Holley that's made to wk with the sniper. Its mounted to my frame. The down side to this is you can hear my fuel pump prime. If my truck was not as loud as it is you could probably hear the fuel pump running.
 

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I wish Edelbrock would make there pro flow with an egr valve cannot pass visual smog inspection without it (New York)
 
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