Help w/Fuel System for Swap
Thread Starter
On The Tree
Joined: Jul 2014
Posts: 143
Likes: 0
From: Lincoln, CA
Help w/Fuel System for Swap Hey Guys,
I'm gathering up the last of the parts I need to do an LS swap in my 84 K5 Blazer and I'm trying to get the fuel system nailed down. I've been reading on here and performance trucks about what people with similar setups have done but wanted to run my list by you folks to see if there's anything I need to tweak and make sure everything's going to work for my setup. Most folks doings LS swaps in these square body trucks just run an AC Delco EP381 pump in the factory sending unit and use a Corvette filter/regulator but I've been reading mixed info about how much HP that setup will support before it starts being a choke point...
The engine I'm using is a stock bottom end LQ9 from an 05 Escalade and I'm swapping on a set of 243 heads with AI's 226cc porting along with a TBSS/Gen IV truck intake with the larger TB and a custom spec'd cam (222/228, 111+3, .604"/.595") from Cam Motion. Not sure on final HP but I'm guessing it'll be 450ish at the flywheel since it'll basically be an iron LS2 with a better cam and heads. So far the plan for the fuel system is:
- 36# truck flex fuel injectors (#12613411) in the factory returnless fuel rail
- Holley filer/regulator (#12-875) rated at 175 gph and preset at 59.5 psi
- Aeromotive 340 lph fuel pump (#50-1000) with their 10ga wiring kit (#16307)
- Summit 6AN braided PTFE hose for the feed & return
- Tank and sending unit from 87-91 K5 Blazer with EFI
The one thing I'm still not sure how to tackle is the wiring at the fuel pump/sending unit. The wiring kit comes with 10ga wires (plain ends) and say to attach to them to the fuel pump but my sending unit has a bulkhead fitting with much smaller 16ga or 18ga wires going to the pump and sending unit with the grounds being combined in to a strap. I'm thinking I should replace that bulkhead fitting and wiring with something like a Racetronix universal bulkhead wiring kit (#BCWS-001) to handle the bigger pump. What do you guys think?
I'm gathering up the last of the parts I need to do an LS swap in my 84 K5 Blazer and I'm trying to get the fuel system nailed down. I've been reading on here and performance trucks about what people with similar setups have done but wanted to run my list by you folks to see if there's anything I need to tweak and make sure everything's going to work for my setup. Most folks doings LS swaps in these square body trucks just run an AC Delco EP381 pump in the factory sending unit and use a Corvette filter/regulator but I've been reading mixed info about how much HP that setup will support before it starts being a choke point...
The engine I'm using is a stock bottom end LQ9 from an 05 Escalade and I'm swapping on a set of 243 heads with AI's 226cc porting along with a TBSS/Gen IV truck intake with the larger TB and a custom spec'd cam (222/228, 111+3, .604"/.595") from Cam Motion. Not sure on final HP but I'm guessing it'll be 450ish at the flywheel since it'll basically be an iron LS2 with a better cam and heads. So far the plan for the fuel system is:
- 36# truck flex fuel injectors (#12613411) in the factory returnless fuel rail
- Holley filer/regulator (#12-875) rated at 175 gph and preset at 59.5 psi
- Aeromotive 340 lph fuel pump (#50-1000) with their 10ga wiring kit (#16307)
- Summit 6AN braided PTFE hose for the feed & return
- Tank and sending unit from 87-91 K5 Blazer with EFI
The one thing I'm still not sure how to tackle is the wiring at the fuel pump/sending unit. The wiring kit comes with 10ga wires (plain ends) and say to attach to them to the fuel pump but my sending unit has a bulkhead fitting with much smaller 16ga or 18ga wires going to the pump and sending unit with the grounds being combined in to a strap. I'm thinking I should replace that bulkhead fitting and wiring with something like a Racetronix universal bulkhead wiring kit (#BCWS-001) to handle the bigger pump. What do you guys think?
TECH Fanatic
Joined: Dec 2017
Posts: 1,462
Likes: 265
From: Bossier City, Louisiana
Your pump might see some voltage drop using that thinner 18 gauge sending unit wire. Pumps need amps so run a dedicated line of that 10 gauge wire and I think you will be better off. A fuel tank sending unit needs much less power and can get away with thinner wire.
Rick
Rick
Thread Starter
On The Tree
Joined: Jul 2014
Posts: 143
Likes: 0
From: Lincoln, CA
Rick, that's what I'm thinking too. Just not quite sure how to do that using the current setup/electrical bulkhead on the sending unit. I'm thinking about getting a new bulkhead kit from Raceteonix to swap out the one that's one there but I'm not sure which one of their kits would be what I need. I shot them an email today to get their input but if anyone else has another suggestion I'm all ears.