Gas tank evaporation canister??? 71 Charger

[71 Charger freak]

Here's the scenario--every morning I open the door to my garage and I get this gas smell that comes in to the house.  My wife has a few choice words for me and the car which prompts me to get the car jacked up this past weekend.  I'm lookin around and on the drivers side I see some tubes running from the top of the gas tank under some panels that looked factory.  So I remove them and see this weird cannister with about 4 tubes running into it from the tank.  Then I start reading all the topics and on about page 70 I saw a blirb about one of these but it just says what it is--not what its purpose is.  So my question is two fold and I'll ask it after I give a little background.

The car is a 71 with a 440 in it.  The fuel comes from the gas tank via a welded in sump with 2-8an lines going into 1-8an line which goes into a Holley125HP electric pump.  An 8an line goes from there to a filter then to the fender to a reducer (6an) and to the carb (a Street Avenger 770).  The original factory pick up has been blocked off.  Two of the four lines to the evaporation cannister are blocked off and two are still there as placed from the factory??

I can smell a stale fuel smell consistently around the back side of the car.  I have checked and double checked the fittings and there are no gas leaks but I still smell it.

Two questions:  1)What is this cannisters purpose?  2)Does anyone have any suggestions for me to get rid this gas smell?   Thanks

[hemihead]

Could also be that the gas vapor is being vented past your gas cap. I believe 71 's still had the vented cap. If that's the case you have to live with it.
Remember these cars are not new cars.They are primitive by today's picky standards.

[2harleyriders]

This was Chrysler's attempt to recycle evap emissions (fuel vapors).  Remove the tank from the rear fender well and see if it is rusted through and check the fuel lines going to it.  They are most likely cracked and need to be replaced.  A new gas cap wouldn't hurt.