LS Swapping your Blazer? Here's how I did an OEM level fuel tank

[phillipm]

I haven't ever posted here but have built many Pro-Touring type vehicles. From this I have learned that GM really knows what's up when it comes to fuel pumps and fuel modules. I thought I would share how I did my fuel tank to have OEM level fuel control for not very much $$.

I bought this 1978 2WD blazer from a guy in Pamono CA. It's a nice truck but definitely needs a lot of the regular items from what I can tell. Plans are to install a 2009 LY6 and a 6L90 Six Speed automatic.



The truck came with a 31 gallon, 13" deep fuel tank. I decided to use a 2006 Chevy truck fuel module, welded in with a Vaporworx SS fuel ring. The fuel ring accepts almost all of the late model fuel modules. So if your tank is a different height you just need to find the correct module that will fit. From there the first step is to cut a 6.375" hole into the tank. I used a hole saw from Home Depot that it normally used for can lights. It's usually located in the electrical isle and not in the tool isle.



One way to do it is use a hole enlarging hole saw kit where you would put a 3.5" hole saw in the original hole and use that to center the larger hole. I have a mill so I used that instead. Either way will work though.





Once the hole is cut simply clean out the tank and get ready to weld in the ring. I used a TIG welder with TIG rod meant for welding SS to standard steel. I buy it from McMaster-Carr but your local welding shop will probably have it too.







Once that's done your ready to install the pump.





One thing to note is the stock fuel sender is 0-90ohm and the new one is 33-240. So a universal sender will be needed. Also you can either use a Vaporworx PWM fuel controller (recommended) or a C5 corvette FPR. Either will work. Total investment is about $500.

[68Timber]

Cool stuff, I don't think I've seen someone retrofit a late model OEM pump to one of these. Is that cheaper than using the typical aftermarket parts?

[phillipm]

It's probably not cheaper. However this pump has a jet pump that passively refills the module keeping it full at all times. We are all used to driving our new trucks down to darn near empty with zero hiccups. This is how it's done. Aftermarket pumps do not have that ability. If you're Looking for OEM level fuel control this is a great option.

[68Timber]

Sorry, I'm on the front side of the EFI learning curve, I didn't know what OEM fuel level control meant. No baffles needed?

[phillipm]

No problem. I've built quite a few fuel injected hot rods and have learned a lot. One is that baffles don't do a whole lot. It's all about fuel buckets. Carl at vaporworx.com has a really informative website too. Check that out of you have time.
Phillip

[mcmlxix]

I used a Vaporworx ring for my 72 Blazer swap but built a custom oversized stainless tank... Love using the factory fuel pump.

[68Timber]

Originally Posted by phillipm

No problem. I've built quite a few fuel injected hot rods and have learned a lot. One is that baffles don't do a whole lot. It's all about fuel buckets. Carl at vaporworx.com has a really informative website too. Check that out of you have time.
Phillip

Thanks man, I'll check his website out. I've pretty much made my mind up to run the FI Tech EFI system, the last question mark has been how best to convert the tank.

Originally Posted by mcmlxix

I used a Vaporworx ring for my 72 Blazer swap but built a custom oversized stainless tank... Love using the factory fuel pump.

I've been following your 78 build and appreciate the details and part numbers you've shared building your fuel system.

[phillipm]

Originally Posted by 68Timber

Thanks man, I'll check his website out. I've pretty much made my mind up to run the FI Tech EFI system, the last question mark has been how best to convert the tank.



I've been following your 78 build and appreciate the details and part numbers you've shared building your fuel system.

If you're using the FI Tech system then you should definitely get their front mounted fuel sump system. It's absolutely awesome.

If anyone wants to know the outcome of how my GM Fuel module is running I can say that it's absolutely as good as a new truck. So good in fact I ran out of gas and it didn't even buck once right up until it ran out! This was a super easy conversion in reality if you have some fab skills.

[ochre 72]

Looks great, thanks for posting that. What did you do to vent the tank?

[phillipm]

In this photo you can see the black 90 degree fitting I snapped on. That is the main vent port out of the fuel tank. The other smaller port goes into the same chamber so you can use either of these. For me, I hooked my vent up to the 2009 Chevy Evap canister which is this size of hose. I also teed into the factory Blazer vent which is up in the filler neck. That way I would hopefully have less issues filling the tank.

As I said this line runs to the Evap cannisters, from there it is controlled by the ecm to purge into the engine. It also has a fresh air vent on there with a vent control solenoid. Basically all this is to keep the truck from smelling up my garage with gas fumes! Nothing I hate more than a truck that stinks up your garage. I always find it funny when people rip this stuff out, not even knowing what it's function is.



Also, here is a picture of my Evap canister mounted under the driver's side of the truck.

[DM72C20]

Old thread but this idea seems very smart. Working on an LS swap into my 72 C20.

You say: "So a universal sender will be needed. Also you can either use a Vaporworx PWM fuel controller (recommended) or a C5 corvette FPR. Either will work."

I've got the entire fuel system that I can use from my 09 Silverado donor truck - aside from the universal sender, would I require the other things? Any Vaporworx controller is at least $400 which is way more than I want to spend on a fuel system.

What universal sender would I want to look at? I think it is just a simple sender that you can drill a hole in the tank and install. I take it the 0-90ohm would work for a 72 stock fuel gauge?

[buffydores]

Phillip hooked me on to this idea and helped me put together my setup. It's money.

[phillipm]

Originally Posted by DM72C20

Old thread but this idea seems very smart. Working on an LS swap into my 72 C20.

You say: "So a universal sender will be needed. Also you can either use a Vaporworx PWM fuel controller (recommended) or a C5 corvette FPR. Either will work."

I've got the entire fuel system that I can use from my 09 Silverado donor truck - aside from the universal sender, would I require the other things? Any Vaporworx controller is at least $400 which is way more than I want to spend on a fuel system.

What universal sender would I want to look at? I think it is just a simple sender that you can drill a hole in the tank and install. I take it the 0-90ohm would work for a 72 stock fuel gauge?

I'm actually using a C5 FPR on my blazer at first, and then I realized the GM module I was using had an internal regulator so I've since removed that. As for the universal sender, yes I just used a VDO universal 0-90 sender and drilled a hole in the top of the tank.

[BlueJeep]

Love this setup, including the retention of the EVAP! What part # did you use for the fuel module? I've used a Delphi FG0402 (2005 Express van w/driver's side doors) in my Jeep, wondering if that's the same as you used here?

Thanks!

[mcmlxix]

Originally Posted by phillipm

In this photo you can see the black 90 degree fitting I snapped on. That is the main vent port out of the fuel tank. The other smaller port goes into the same chamber so you can use either of these. For me, I hooked my vent up to the 2009 Chevy Evap canister which is this size of hose. I also teed into the factory Blazer vent which is up in the filler neck. That way I would hopefully have less issues filling the tank.

As I said this line runs to the Evap cannisters, from there it is controlled by the ecm to purge into the engine. It also has a fresh air vent on there with a vent control solenoid. Basically all this is to keep the truck from smelling up my garage with gas fumes! Nothing I hate more than a truck that stinks up your garage. I always find it funny when people rip this stuff out, not even knowing what it's function is.



Also, here is a picture of my Evap canister mounted under the driver's side of the truck.

Phillip... do you have the part number for the 90° fitting

What about hose? Nylon? What size?

[phillipm]

Originally Posted by BlueJeep

Love this setup, including the retention of the EVAP! What part # did you use for the fuel module? I've used a Delphi FG0402 (2005 Express van w/driver's side doors) in my Jeep, wondering if that's the same as you used here?

Thanks!

I can’t remember the exact pump but that’s pretty much what this is as well. I think early in this thread I may have written it down? Been a long time!
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[phillipm]

Originally Posted by mcmlxix

Phillip... do you have the part number for the 90° fitting

What about hose? Nylon? What size?

I’m using Gates Barricade hose on everything. 5/8 for large evap and 3/8 for fuel feed. 1/4” hardline (aluminum) for the evap purge line to the engine.
Posted via Mobile Device

[BlueJeep]

Originally Posted by phillipm

I can’t remember the exact pump but that’s pretty much what this is as well. I think early in this thread I may have written it down? Been a long time!
Posted via Mobile Device

Where did you find the specs? I lucked out when I spec'ed it out for my Jeep, as I had the van that the engine came out of and the van tank was within 1/8" of the same depth as my fuel cell.....so I used it.

[phillipm]

Yep I just used RockAuto to go from vehicle to vehicle looking for a pump of the right depth. I don’t remember it taking too long to find one because many of the pumps have about a 1.5” range they can work within. Especially on the truck versions.
Posted via Mobile Device

[BlueJeep]

Originally Posted by phillipm

Yep I just used RockAuto to go from vehicle to vehicle looking for a pump of the right depth. I don’t remember it taking too long to find one because many of the pumps have about a 1.5” range they can work within. Especially on the truck versions.
Posted via Mobile Device

Thanks, I hadn't checked there! I was on Delphi's website but they don't list depth as a spec. Do you bias towards one certain brand of module?

[phillipm]

I just try to run OEM as much as I can. There are reasons new cars go 100k miles without needing a fuel pump. I've been let down by aeromotive and other aftermarket pumps more times then I care to share. Those companies have a place, but 5k miles on hot rod power tour and other constant use applications IMO are not those. In my blown LS6 Cutlass I'm running an LSA CTSV pump. It's awesome. Again, controlled by a PWM from Vaporworx

[BlueJeep]

Originally Posted by phillipm

I just try to run OEM as much as I can. There are reasons new cars go 100k miles without needing a fuel pump. I've been let down by aeromotive and other aftermarket pumps more times then I care to share. Those companies have a place, but 5k miles on hot rod power tour and other constant use applications IMO are not those. In my blown LS6 Cutlass I'm running an LSA CTSV pump. It's awesome. Again, controlled by a PWM from Vaporworx

I'm a 5 time Long Hauler, so I know exactly what you mean. I lean towards Delphi on the fuel module, but wondered if others were of similar quality.

That said, I've also pulled the bed off my truck alongside the interstate at 4am in Ohio on the way back from the last stop on the power tour and swap out the fuel pump (AC Delco) just to find out it wasn't the fuel pump, it was the crank position sensor....Dohh!

[phillipm]

Originally Posted by BlueJeep

I'm a 5 time Long Hauler, so I know exactly what you mean. I lean towards Delphi on the fuel module, but wondered if others were of similar quality.

That said, I've also pulled the bed off my truck alongside the interstate at 4am in Ohio on the way back from the last stop on the power tour and swap out the fuel pump (AC Delco) just to find out it wasn't the fuel pump, it was the crank position sensor....Dohh!

Doh!!!!
Posted via Mobile Device

[BlueJeep]

To follow this up with some part#'s for others, I also am going to use the 31 gallon (suburban) tank, with a ring welded on top similar to this. The tank is right at 12" deep, and the Delphi FG0402 fuel pump (internally regulated) has a useable range of about 11" deep to 13" deep, so this tank is right in the middle of that useable range. Perfect!

Thanks Phillip for all the great information!