Fuel Lines and My Small Block

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OldSchool C-10

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Almost ready to fire mine up and have a question about the fuel lines on my '83 C10. I put a new fuel tank and sending unit in before I bought the engine. Now that the engine is in I remembered that the sending unit has two fuel lines coming out of it but the engine only has one gas inlet. The old 250 had all the smog stuff and and canister on it so I'm assuming I can leave the canister off, or can I?.

Which of the lines coming out of the sending unit needs to be blocked?
 

fast 99

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Smaller one, will need a vented gas cap and I don't believe the screw on style cap was ever vented. May need to punch the center out.
 

Ricko1966

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Personally I'd keep my fuel system sealed and run the canister,it's not the easy way but it keeps fuel from evaporating and keeps moisture out of the gas tank. @SirRobyn0 put up some pretty good information about plumbing the charcoal cannister. If you do go vented gas cap I'd use a 3 port fuel pump and use the open sender port for fuel return.
 

CalSgt

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Personally I'd keep my fuel system sealed and run the canister,it's not the easy way but it keeps fuel from evaporating and keeps moisture out of the gas tank. @SirRobyn0 put up some pretty good information about plumbing the charcoal cannister. If you do go vented gas cap I'd use a 3 port fuel pump and use the open sender port for fuel return.
^^^^ This

Take the extra time and hook up your evap canister. All the benefits above plus your truck and garage won’t constantly stink like gasoline vapors.

ETA: Also Greta Thurnberg approved this message
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Bextreme04

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do you have a vent or a return line on the sending unit? Most 80's and later squares would have a feed and return fuel line, plus a vent line on the sender.
 

SirRobyn0

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Thanks for bringing me in this thread @Ricko1966

Besides the fact that without a canister system you'll literally let some of your gas dollars evaporate, but when the fuel contracts, or you drive the truck and burn the fuel you'll be pulling in any moisture in the air. Gasoline hates moisture and E-10 hates it even more. Setting that aside moisture in a metal tank is a recipe for rust. Most old cars or trucks we see at the shop with rusted fuel tanks have one thing in common. A removed or inoperative canister system. The problem is a lot of people misunderstand them or don't have clue how to hook them up or what vacuum lines connect to where when in reality it's quite simple. Which is why I wrote this tutorial. Link here >>> https://www.gmsquarebody.com/thread...should-be-set-up-and-other-information.37324/ <<<
 
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