Mechanical fuel pumps

[DavesJimmy]

Just bought the holly sniper efi master kit from a local performance shop here in town. I also read its preferred to install pump in tank but not mandatory. So im going to mount outside for now. I contacted Tanks inc. Via email they have a chevy truck tank for a 6' bed already converted for efi. But im not sure if it'll fit in my 76 gmc. If it will ill probably go that route.

 

[Frankenchevy]

Not sure about the fit of a truck tank on a jimmy. What about an 87 blazer tank...will that bolt up? I’m just thinking out loud and have no experience with blazers, but the 87 model year tanks should be baffled for in tank pump/sender.

If you can use an 87 tank and sender with a 96-99 fuel pump like the ac delco ep381, it’d be all parts you can replace at a local parts store.

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[hatzie]

For a pickup body... You can use a 16 gallon tank for a 1987 RV series shortbox squarebody along with a Delphi fuel-pump & sender assembly for the same rig... parts purveyors like RockAuto call the fuel pump and sender a "fuel pump & housing assembly"
The 87-91 tanks have baffles for the TBI fueling setup.

RockAuto has the 1987 tanks between $60 & $90.

The OEM 1987 RV series GMC/Chevy pickups Delphi HP10021 Fuel Pump and Hanger Assembly with Sending Unit Fuel Pump and Sock is around $90. There are less expensive alternatives from Spectra for about $50 but the senders don't seem to be the same quality... bouncy needles and cheaper fuel pumps.

The only mildly exciting part is adapting the fill hose diameters. Earlier had 1-3/8" filler necks. Later were something like 1-3/4"... I modded the 76 filler necks using steel exhaust pipe reducer, my TIG, and Parker bead tool to mate with the larger hose. If you have a later bed with the door(s) you can just convert to the later larger diameter filler neck by changing the bolt-in parts behind the filler door. The additional 5/8" filler diameter and raised filler height makes a big difference in how easy it is to fill... even the expansion in filler diameter just a few inches down from the lower 73-77ish opening in my bedsides made a big difference.

 

[hatzie]

I missed the fact you're working on a K5 Blazer.

The stock GM Fuel pump/sender/sock assembly for the 1987 31 gallon K5 Blazer tank is Delphi HP10026... it's around $155 at RockAuto. Worth every penny IMHO... and about what you'd pay for the cheap spectra sender and the GM fuel pump.

Just swap out to the 87-91 31 gallon Blazer tank and adapt the 73-77 filler neck to fit the larger diameter fill and vent hoses on the 87 tank.

 

[Frankenchevy]

Make sure whatever pump you get puts out the correct gph at 60psi. ‘87 pumps were ~12psi

 

[hatzie]

Make sure whatever pump you get puts out the correct gph at 60psi. ‘87 pumps were ~12psi

Good point. Get a Walbro pump not the cheapies. It's in the tank. You don't want to pull it down because the fuel pump you chose was not up to the task.

Fish aroud a bit. Delphi made the RV series sender/fuel-pump-hangar assembly without the fuel pump. You will get the pleasure of properly terminating the fuel pump hookups because the OEM fuel pump plug is not likely to fit the 60PSI pump. I like the Walbro GSL pumps because they are terminated with ring terminals. Pick one that's listed as submersible in fuel with the required LPM or GPM flow ratings and the correct PSI rating.

If you can mount the Holley pump at or even a little below the bottom of the fuel tank you'll probably get away with the stock 76 tank and sender for quite a while. The 73-86 tanks don't have pickup sock baffles to keep the pickup in fuel below about 1/4 tank or so... so you don't want to run it below 3/8 of a tank and take hard corners.
If you stick with the external pump you can still upgrade the tank to the 87-91 with baffles and keep the 76 sender.
If the Holley pump blows out on you the external Walbro GSL series pumps are a nice outside the tank choice. Pick one that has the required LPM or GPM flow rating and the required PSI.

 

[Craig 85]

Have you guys seen these Holley pick up mats? I saw a show about these a while back.
http://www.superchevy.com/how-to/additional-tech/1508-holleys-new-hydramat-fuel-pick-up-system/

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[hatzie]

The RV series senders fit the older tanks.

Using that system in place of the pickup sock in the original tank is a slick way to avoid the filler neck dance.

Have you guys seen these Holley pick up mats? I saw a show about these a while back.
http://www.superchevy.com/how-to/additional-tech/1508-holleys-new-hydramat-fuel-pick-up-system/

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[HotRodPC]

How much fuel pressure does the Holly EFI require? I'm thinking finding a used tank from an 87 up K5 would work fine if you needed to cheap out. Those TBI tanks are also sumped and baffled unlike the carb truck tanks. The TBI fuel pump is likley good enough too since the Holly EFI appears to be a TBI type system.

 

[Frankenchevy]

How much fuel pressure does the Holly EFI require? I'm thinking finding a used tank from an 87 up K5 would work fine if you needed to cheap out. Those TBI tanks are also sumped and baffled unlike the carb truck tanks. The TBI fuel pump is likley good enough too since the Holly EFI appears to be a TBI type system.

Needs 60psi or more. It’s internally regulated at 58.5psi, I think..

 

[HotRodPC]

Needs 60psi or more. It’s internally regulated at 58.5psi, I think..

Wheww, them are some healthy injectors then. I don't think even a SFI Vortec fuel pump requires 60psi. I'd for sure go with an in tank pump for that set up.

 

[Frankenchevy]

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[HotRodPC]

Is this Holley Sniper a 4 injector system or just 2 like OEM TBI?

 

[DavesJimmy]

Well i got the holley sniper efi master kit it comes with the fuel kit part # 526-5. Which is ment for vehicles that already had tbi. There 526-7 is for later vehicles that where not factory tbi so it comes with a few more parts, extra hose etc..After doing a lot of reading i found out. The fuel pump in the kit cant be mounted in tank
And it comes with 20' of 3/8" hose and ill probably need 40'.. so im going to buy the extra hose for the return line... install the kit per instructions so i can drive it asap cause its my daily.. then im going to buy an 87 fuel tank & sending unit. And a efi fuel pump i can mount in tank.
Get it all put together so all i have to do is drop old tank and connect new setup..i shoulda just got the sniper non master kit.. thanks for all the input.

 

[DavesJimmy]

Is this Holley Sniper a 4 injector system or just 2 like OEM TBI?

Its a 4!