1971 fuel line routing

[Cody4president]

I'm trying to fix a hack-job on the fuel tank vent system on my 71 440 R/T and I'm looking for advice on both how it was supposed to be plumbed and any suggestions to improve it.  There seems to be a bit of info out there on '70 and earlier and '72 and newer, but I'm getting the impression that the '71 fuel vent/emissions control system was its own beast.

What I'm seeing so far is 4 nipples on the drivers side of the fuel tank that all appear to connect to the overflow tank in the wheel well.  The overflow tank has an additional 1/4" nipple that connects to a solid vent line that goes over top of the fuel tank cavity and joins up with the 3/8" fuel supply line and an additional 1/4" vent line from the fuel sending unit.  All three of those lines go forward along the passenger side undercarriage to the engine compartment.  The supply line connects to the fuel pump, but I'm lost as to where to connect my two 1/4" vent lines.  One line stays low and ends by the fuel pump and the other bends upwards towards the top of the engine compartment, ending near the heater core. 

My questions:  are the vent lines supposed to be routed through a charcoal canister?  Do they both end up in a PCV or the air filter assembly?  Are there better ways to route the vents than the factory way?

Any help would be appreciated, thanks!

[BLK 68 R/T]

Main line to fuel pump, return line from vapor separator, 3rd line up top connects to the valve cover breather.

[71 SE3834V]

Did the 440 have a 3rd line to the engine compartment? My Nov. build 383 only as the main line and the line up the inner fender to connect to the 3 nipple breather. No vapor separator or charcoal canister under the hood.

[Cody4president]

Yeah- mine has 3 lines.  The main fuel supply line and what I assume is vent/return lines.  One from the sending unit in the tank and one from the rear driver-side wheel well vapor separator.

[Alaskan_TA]

Some info at http://www.hamtramck-historical.com/images/serviceHighlights/1971/1971%20service%20highlights%20%2058.jpg

1970 & 71 440s & Hemis also used an additional vapor separator near the fuel pump (this illustration is from the 1970 FSM)

[4aThrill]

Some info at http://www.hamtramck-historical.com/images/serviceHighlights/1971/1971%20service%20highlights%20%2058.jpg

1970 & 71 440s & Hemis also used an additional vapor separator near the fuel pump (this illustration is from the 1970 FSM)

This is what I did only seemed logical because if you block off the vent line which most people do then your gas tank will just expand with heat under pressure right, and how is that really safe?  Yes your gas cap is vented but that's if it works too.  So with that canister you can get it at Dixie restoration I believe for a decent price I would pick up two just to cover the price of shipping.