Dual Tanks Vs Single 40 Gallon Tank For 8.1l Swap

[Gilderbeast]

What would be the best route to go? I have a 1980 K30 with dual tanks but one is rusty inside. Neither have electric pumps. Would it be easier and cheaper to just get a 40 gallon suburban tank? What components do I need for the fuel system for the 03 8.1l?

 

[ajd89]

What would be the best route to go? I have a 1980 K30 with dual tanks but one is rusty inside. Neither have electric pumps. Would it be easier and cheaper to just get a 40 gallon suburban tank? What components do I need for the fuel system for the 03 8.1l?

From the searching I've been doing for my 8.1 lve come to the conclusion that basically the fuel system would be the same as a ls swap. 87 efi tanks ep381 fuel pump and high pressure lines.

 

[Gilderbeast]

From the searching I've been doing for my 8.1 lve come to the conclusion that basically the fuel system would be the same as a ls swap. 87 efi tanks ep381 fuel pump and high pressure lines.

I thought you needed something after the tank switch?

 

[75gmck25]

Another option is to install an external surge tank or somthing like the Go EFI Fuel Command Center. https://www.summitracing.com/parts/hpf-40004

The surge tank holds about 1.5 quarts of fuel, and has a high pressure pump immersed in the fuel. You use a stock mechanical or electric low pressure pump to feed the surge tank filled, and its high pressure pump provides the high pressure fuel for you EFI. Most surge tanks also include the fuel pressure regulator and return line connections, so it provides all the functions you need.

A good surge tank setup is relatively expensive, but lets you keep the stock fuel tanks and lines in place (including the dual tank setup), without any need to run new return lines or add switching valves, or switch to newer EFI tanks.

Bruce

 

[Madhorn]

When I did my LS swap the surge tank idea was one option that was seriously considered. It is probably the best option if you are wanting to keep factory dual tanks. If I have my thoughts straight, the 8.1 used a high pressure electric fuel pump in the tank. If you use a surge pump set up you will need a low pressure electric lift pump between the fuel tanks and the surge tank. In the end, I am big fan of a single tank with the pump in the tank. Just my opinion. Currently I am running a single 16 gallon tank for an 87 EFI C10, (has electric pump baffles) with an ep381 pump. Yes, the single 16 gallon tank does limit my range to about 175 miles, but I am not taking cross country road trips, so its not a big deal to me. One day I may go back and install a suburban tank behind the rear axle.

 

[C10MixMaster]

What would be the best route to go? I have a 1980 K30 with dual tanks but one is rusty inside. Neither have electric pumps. Would it be easier and cheaper to just get a 40 gallon suburban tank? What components do I need for the fuel system for the 03 8.1l?

my dual tanks are a love hate kinda thing love having them but filling up you have to turn the truck around kind of a PIA. You can do in tank pumps although it is at the upper end of the pressure the switching valve can take 8.1 runs 58 psi stall the valve is rated to 65 psi . you can do low pressure in tank pumps and a hi pressure pump after the switching valve this is a common way the European cars do it. If you are OK with the suburban tank its bigger, only one pump to deal with, no switch valve to go bad basically simpler once installed. plus now all that weight behind the rear tires is helping with traction for the big block.

 

[Frankenchevy]

In the installs I’ve read re: the 40 gallon burb tank, you only end up with 2-4” clearance to the diff. 2” if you keep stock crossmember, 4” if you use a burb crossmember and slide it far enough back, iirc.

Even 4” is nowhere near enough for me to feel comfortable. Between that and actually needing to use my bed(not wanting the filler in the bed floor), I opted to keep my dual 20s. I think smaller tanks will offer more clearance and there are creative ways to route the filler.

I almost always fill up at Costco and their pumps reach both sides. Plus, it’s interesting to see the disappointment on people’s face when they think I’m done filling, only to see me walk around to the other side and start over again.

 

[CSFJ]

Park in between the pumps, run one from each island.

 

[Remo76C15]

Stock

 

[Gilderbeast]

In the installs I’ve read re: the 40 gallon burb tank, you only end up with 2-4” clearance to the diff. 2” if you keep stock crossmember, 4” if you use a burb crossmember and slide it far enough back, iirc.

Even 4” is nowhere near enough for me to feel comfortable. Between that and actually needing to use my bed(not wanting the filler in the bed floor), I opted to keep my dual 20s. I think smaller tanks will offer more clearance and there are creative ways to route the filler.

I almost always fill up at Costco and their pumps reach both sides. Plus, it’s interesting to see the disappointment on people’s face when they think I’m done filling, only to see me walk around to the other side and start over again.

Not sure if it helps but I have 1 ton (2" taller frame height) with 4" lift. I don't plan on offroading it.

 

[Frankenchevy]

Not sure if it helps but I have 1 ton (2" taller frame height) with 4" lift. I don't plan on offroading it.

Mines a 1-ton as well, but I don’t think they’re 2” taller in the rear section of the frame. Don’t know for sure though.

 

[Gilderbeast]

Mines a 1-ton as well, but I don’t think they’re 2” taller in the rear section of the frame. Don’t know for sure though.

Well I assume the extra 4" of lift helps at least.

 

[Frankenchevy]

Lol, definitely. Do it. I’d like to see some actual clearance numbers with this mod on a k30.

 

[Gilderbeast]

Lol, definitely. Do it. I’d like to see some actual clearance numbers with this mod on a k30.

Yeah its cheaper, less components to go out, one tank to fill, adds traction to the rear wheels which will help me in the winter. I think the only cons is/are possibly hitting the rear differential and when the one pump goes you're screwed but I'll probably setup a backup pump just in case.

 

[Camar068]

Yeah its cheaper, less components to go out, one tank to fill, adds traction to the rear wheels which will help me in the winter. I think the only cons is/are possibly hitting the rear differential and when the one pump goes you're screwed but I'll probably setup a backup pump just in case.

another is relocating the filler. I drilled a hole in the bed for mine. Plan is to get a door relocated at the rear.