want to add a return line with duel tanks?

[JD1973]

hey everyone:
Maybe this has been asked before, But I want to add a return line in my 73 K10, this is more of a preventive measure with the summer already heating up,
Has anyone here added one with fuel tanks, this truck didn't come with dual tanks, I added the driver side tank years ago.
what have you done, did you add use the 6port selector valve?

have a great day

 

[CalSgt]

6 port Pollack valve and '87 sending units have provisions for feed, return and vent. Maybe some other years too but not sure.

I only changed to go EFI.

 

[Bextreme04]

6 port Pollack valve and '87 sending units have provisions for feed, return and vent. Maybe some other years too but not sure.

I only changed to go EFI.

hey everyone:
Maybe this has been asked before, But I want to add a return line in my 73 K10, this is more of a preventive measure with the summer already heating up,
Has anyone here added one with fuel tanks, this truck didn't come with dual tanks, I added the driver side tank years ago.
what have you done, did you add use the 6port selector valve?

have a great day

87 is the only option for EFI, the sending units have provisions for an in-tank fuel pump. For any application using a carb, just use the appropriate year sending unit with 3 ports(Feed, Return, Vent). You should currently have a 2 port(Feed, Vent).

https://www.lmctruck.com/fuel-system/gas-tanks-parts/cc-1973-87-side-mount-gas-tank-and-components

What switching valve did you use when you added the drivers side tank? You can either add a second 3-port valve or swap the one you have now for a 6 port.

 

[Radiohead]

'79 has the return system. Carb only.

 

[1982GMCC1500]

I have an '82 with OEM dual tanks. The engine would starve for fuel even though I was using only the left tank. New tanks and senders, but still had the original valve, which I thought was bad. When I ordered a new valve from Amazon, it was not correct because of the hose diameter ports. The truck still has the charcoal cannister, but it is not hooked up in it's entirety....So as of right now, I bypassed the valve to run on left tank

 

[Ricko1966]

I have an '82 with OEM dual tanks. The engine would starve for fuel even though I was using only the left tank. New tanks and senders, but still had the original valve, which I thought was bad. When I ordered a new valve from Amazon, it was not correct because of the hose diameter ports. The truck still has the charcoal cannister, but it is not hooked up in it's entirety....So as of right now, I bypassed the valve to run on left tank

If the charcoal canister is not hooked up correctly that can cause fuel starvation problems.

 

[AuroraGirl]

If the charcoal canister is not hooked up correctly that can cause fuel starvation problems.

its like plugging the vent in an old vented cap and and before you collapse the tank youre wondering why you cant get hardly any fuel in the fuel line

 

[73 cheySuper]

I just hunted down Pollak 6 ports and couldn't find one that said it'd fit my '73. Probably worth a phone call to them, but it'd be much appreciated if someone would post a link to the correct valve. I've got twin tanks, return line, and no charcoal canister. Honestly I thought all chevys had charcoal canisters after '70, but am basing that on cars, not trucks. My oem passenger side tank had 2 ports on the sender and a return on the fuel pump. The driver's side tank was added somewhere along the way, it too had a 2 port sender. I tossed both of those senders, stupid me, usually keep all old parts until the bugs are ironed out. The interesting thing...the small port on both new senders is 5/16", the main feed 3/8". The return line is 1/4". I tied the 5/16 in with the 1/4 return, but that tells me something is weird.
Sidenote.......virtually ALL the new fuel pumps that have return line provisions have the tube feeders hanging down too low and hit the frame crossmember on a K20. Had to pocket that member to make it work.....total bitch. Comparing it to my original pump, it was at least 3/8" lower.

 

[Craig Nedrow]

New For Me 1985 Silverado 20 6.2 Diesel

Maybe the camper shell is for an OBS GM truck, I think they're a little bit more narrow at the top of the bed/box.

www.gmsquarebody.com

Start at post 65, complete fuel system install with part numbers etc. Floats did have a return line in them, I had a diesel, so just capped the extra port.

 

[JD1973]

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found this looks promising