'71 Jimmy Gas Tank plumbing & venting

[DC_Jimmy]

Finally taking a look at fuel lines on '71 Jimmy that's been sitting up way too long. Has a newish replacement gas tank in it, no idea if appropriate tank model - truck has lots of lazy hacks on it from previous owner.

Did the '71 originally have a charcoal cannister? If so, would you add back missing cannister?

If no cannister, should I rely on vented cap or run vent line(and terminate where?)?

What is proper method of capping the unused fuel return port on passenger side of tank?

Thanks for all your expertise.

[DeadheadNM]

If I recall, these pics are of a 71 and that charcoal can was used for the 72 model year. The fuel tank plumbing differs for 72.

[DC_Jimmy]

Many Thanks, very clear pics.

So I'm seeing the '71 tank had two vapor lines running to the (not pictured) steel pipe vapor collector(?) and then 1 vapor line running from steel pipe junction up to carb or manifold?

My truck like many is missing the original vapor collector steel pipe in bed. What have most done when missing the steel pipe?
Retrofit a charcoal cannister or just terminate vent lines with breathers (like a differential vent hose)?

[1rippen6]

I have the evap. tube in the bed if you need one. I can get pictures Tuesday if interested.

[DC_Jimmy]

Thanks rippen. To clarify, the evap. tube in bed, is that designed to temporarily hold fuel that may make its way up the vent lines? I've noticed the vent tubes on my tank do seem to spit fuel if overfilling the tank.

[1rippen6]

I have no clue how the system is supposed to work, sorry. Here is the tube I have 35 plus shipping .

[SeventyOne]

Those are my frame pics above. It is a 71 and it also has the charcoal cannister.

[Harold Holbrook]

Great Pictures, Does it mater what lines go those 3 vent tube lines?

[1rippen6]

Originally Posted by Harold Holbrook

Great Pictures, Does it mater what lines go those 3 vent tube lines?

I would think so, I believe DeadheadNM has posted a schematic of the fuel lines before.

[DeadheadNM]

Bumped it up w a new photo - see here: https://67-72chevytrucks.com/vboard/...98#post8812698