Trying to figure the best way to vent my fuel tank in my 71' Duster. Originally it had the vapour seperator with the 4 tubes from the fuel tank and the tube in the trunk that ran to the engine which was long gone when I got it.

It also has the 72 and up style tank with a single vent line to run to a charcoal cannister under the hood.

Can I vent off the tank vent under the car or will I get fuel slosh from that tube?

I've also seen some where they have a nipple on the fuel filler tube with a vent that goes under the car.

I have the exact same question on my '73 cuda...

All my vents are capped and I run a vented gas tank. I put a 73 tank into my 74 and those years have a completely different venting system so this seemed like the easiest way out. At first I ran a non-vented cap and it tank developed a vacuum inside and when I took the cap off at the gas station I could physically see the gas tank expand a little! Changed to the cheapie plastic parts store locking vented gas cap and problem solved. Don't have pressure or vacuum build up and never leaked gas.

You can vent under the car, you just need the vent line to go up high first, before it is turned down. The factory ones I have seen, went up through the trunk over the axle area, up under the rear deck ( where speakers mount ), and then back through the axle area and out under the car.

My 1972 Charger gas tank was leaking at the 4 vent tubes whenever I filled the tank. I had them removed, welded up and tank sealed by a pro shop. I now just vent to atmosphere thru a Stant #11646 fuel cap instead of original vented/pressure-relief cap. May work for you, may not. Doesn't fit quite as tight as original fuel cap but tight enough. No more leaks, works great. If you can find a Stant catalog with dimensions and pics you should be able to find a good vented cap that will fit.

I ran a hose to a small K&N filter for a vent.



Ken

I've had no luck finding a vented cap for an A-body, plus the stant one I bought didn't fit at all it was very loose.

So If I route a line off the factory nipple that went to the charcoal cannister high enough and with somthing on the end to keep the crud out it should vent well enough?

My other idea was to reomove the filler tube and put a nipple on it for a hose and vent that way.

The first option is the least amount of work though.

Route it high, and back down again. It works. You shouldn't need anything over the end.